Being harder to parse is not a trivial detail, it's the whole ballgame. Written language has a lot of redundancy. That's one of the things that makes it work. The redundancy makes it an error-correcting code so that the information doesn't get dstryed by miner errers. That is what allows you to glean the meaning of a message even without whitespace. Y cn d th sm trck by lmntng vwls (u o eiiai ooa).
Just because you don't completely destroy the message by eliminating whitespace doesn't mean that the whitespace wasn't semantically significant.
[UPDATE] Whitespace is actually a pretty modern innovation, and it is not universal. In old manuscripts the text is often allframmedtogetherlikethis. Also, even in modern German it is common to compose verylongcompoundwords.
Back around 2006, there was an internal collection of quotes from senior Google engineers. There was one from a guy working on a particularly thorny issue with Russian search. He had just finished a project on Thai segmentation, and his response to how things were going with Russian was something like "Great! At least they have words!" (Obviously, he was being deliberately imprecise and understood that obviously Thai has words, just not whitespace-delimited.)
On a side note, the Korean alphabet is well-designed. In particular, teaching children syllabification rules is trivial. Syllables are pre-arranged into squares. Unfortunately, the lack of distinction between r-l, and p-b-f, and restrictions on consonant clusters makes it unworkable as a replacement alphabet for English.
Just because you don't completely destroy the message by eliminating whitespace doesn't mean that the whitespace wasn't semantically significant.
[UPDATE] Whitespace is actually a pretty modern innovation, and it is not universal. In old manuscripts the text is often allframmedtogetherlikethis. Also, even in modern German it is common to compose verylongcompoundwords.