It's called "appeal to authority", and it's a fallacy only in case where the authority is not relevant to the area in question. So, if a Nobel prize winner in literature gives advice on economics or quantum physicists or medicine, then their credentials are irrelevant, and appeal to their authority is a fallacy. If, however, a prominent physicist talks about physics, then it doesn't mean they are necessarily right, but at least the likelihood of them being right is much higher than for a random person from the street. As such, having created successful technical products in the past suggests that it's likely next product may be worth something too. It's not a guarantee, but it's a relevant data point.
> haven't done much in a long time
All right, but apart from the sanitation, the medicine, education, wine, public order, irrigation, roads, a fresh water system, and public health, what have the Romans ever done for us?
> All right, but apart from the sanitation, the medicine, education, wine, public order, irrigation, roads, a fresh water system, and public health, what have the Romans ever done for us?
I think you're giving him too much credit. This is the guy who cursed us with JavaScript and set back Web development by a solid decade, then went on to say "fuck you" to same-sex marriage before getting fired from his newly-attained CEO chair of Mozilla. His contributions to the world at large are more akin to the French: he added a lot of fancy, useless things to the world and then cowered and backpedaled when he was questioned for his beliefs.
> haven't done much in a long time
All right, but apart from the sanitation, the medicine, education, wine, public order, irrigation, roads, a fresh water system, and public health, what have the Romans ever done for us?