I imagine he's in a hard position. He makes fonts for TV shows / games / etc, and they tend to be silly/weird/unique. He kinda needs to use his own typeface for his blog, and he doesn't have a lot of "sane" options to choose from!
Sans-serif is typically not a very good fit for body texts. The line-height is also set too low, makes it harder to jump to the next line as you try to find which one it is.
This is absolutely correct for books, but a blogpost is not a book. The most significant reason to use sans-serif for UI text is that screens with less DPI tend to utterly destroy serif fonts with small font sizes. Serif fonts just rely that much more on high DPI values like on a book. If you somehow have an audience that's exclusively on Retina displays (e.g. for iPad/iPhone apps), I would be less hesitant to try out a few serif options. But designers tend to forget that e.g. not all desktop users are on color-graded 5K iMacs.
I’m curious where you heard that sans-serifs are not a good fit for body text.
Sans-serifs has been a popular choice for body text on posters, backcovers (of books, albums, board-games etc.), user interfaces, instruction pamphlets, social media, blog pages, etc. I honestly have no idea where a recommendation such as this could originate from.
"Don't use sans-serif typefaces for body text" has been age-old advice in the print world, on the principle that long blocks of text -- e.g., not posters, back covers, or instruction pamphlets, but short stories, novels, feature stories, newspaper and magazine articles -- is easier to read with serif type. In the print world, long-form text like that is overwhelmingly set in serif faces, not sans-serif.
Sans-serif type became the standard in on-screen computer contexts in no small part because at 75–100 PPI resolution, monitors just couldn't render delicate features particularly well; even good anti-aliasing is going to turn the serifs on 12-point text into gray smudges. Computers just did better when you went to sans-serif fonts, particularly ones designed with relatively high x-heights and big counters like Verdana.
I do wonder if the preference for serifs in long text bodies in print media is due to a reasons of historic technical limitations similar to the low PPI resolutions on older screen displays.
For example. It is easy to imagine older print technology being prone to ink bleed (particularly on mass print media such as books and news papers) which becomes very visible on small the smaller font-sizes prominent in the same media. I can also see how such bleed would be more disruptive without the serifs and the serif fonts would then be preferable.
With modern printers (or screen displays for that matter) such concerns would be as obsolete as the concerns that the serifs turn into smudges on low resolution screens.
The serifs have appeared for the first time in the Latin inscriptions cut in stone.
So if there was any technological reason for them, it was either due to the stone carving techniques, or more likely to the limitations of writing with a wide brush, because the stone was carved after the letters had been painted with a wide brush, to guide the carving.
After the Imperial Rome, the serifs have continued to be used when writing on different supports mainly due to tradition.
The serifs are not the only difference between serif and sans-serif typefaces, the second difference is that the sans-serif letters are drawn with lines of uniform width, while the serif letters are drawn with a combination of thick lines and thin lines.
There are some modern sans-serif typefaces, like Optima and many others inspired by it, which are intermediate between classic serif and sans-serif typefaces, by lacking serifs but using variable-width lines, like the serif typefaces.
Even if the serif fonts are the traditional fonts, used almost exclusively until the 19th century, when the sans-serif fonts became popular for certain uses (e.g. for titles, for advertising or for newspapers printed on cheap paper) there are good reasons to use them besides the tradition.
Their 2 extra features, serifs and variable-width lines, make the letters more distinctive, less similar to each other, and in the opinion of many people, more beautiful.
Because of that, when rendered at very high resolutions, most people consider the serif typefaces more legible, even if there are also younger people, who have read few books on paper, but who have been accustomed with reading sans-serif typefaces on low-resolution displays, so they may prefer the sans-serif typefaces.
As another poster has already said, the advantages of serif typefaces are achieved only at high resolutions, i.e. preferably on 4k displays or better and when not using stupid dpi scaling, but actually using the high resolution for rendering. On the many garbage laptop displays with low resolutions, the sans-serif typefaces are almost always better.
I want to add that why I am not completely convinced that it is better for the letters to have serifs, I definitely believe that the letters drawn with constant-width lines are much uglier than the letters drawn with variable-width lines.
Because of that, even if I use frequently sans-serif typefaces, I use only non-traditional sans-serif typefaces with variable-width lines, e.g. Optima Nova, Palatino Sans or Trajan Sans.
However, such typefaces with variable-width lines also need high-resolution displays to be useful. On displays with less than 4k resolution, their appearance at normal text sizes is degraded.
So would you then say that the popularity of sans-serifs as body text on printed media such as posters, back-covers, consumer packages, etc. is due to them preferring style over legibility?
It's an interesting question. I know that ink bleed was taken into account in type design, which actually led to some early digital versions of classic typefaces being poor renditions because they were too literally following the cuts of the metal and ended up being too thin.
The traditional rationale I come across is that serifs "lead the eye," but I have no idea if there's any real research about that. There's probably some truth to broadly stereotyping sans-serif fonts as generally more legible and serif fonts as generally more readable -- but I'm sure there's a myriad of exceptions. (Like, uh, Myriad, a sans-serif explicitly designed to be good for body text.)
I can't tell if that's ironic or not.