Seems obvious.
Any player being a dick is just gonna get evicted for being a smart ass. See how that works?
Hang on a tick here. In what way am I being a dick? I'm asking for clarification. Now, if you don't know much about Egyptian history, that's fine, no problems. Or, if you DO, that's fine too. But, considering that Egyptian history spans several thousand years, to the point where Cleopatra is closer to us timewise than to the original pyramid builders, then asking what an "Egyptian themed" campaign is isn't exactly a stretch here.
But, again, this seems to be the common refrain. Asking questions is to be discouraged. Any questioning is seen as "attacking" the DM when nothing could be further from the truth. It's perfectly reasonable to look at the DM's restrictions and then question why they exist.
For example, when I ran my Thule campaign (5e), I restricted classes to non-full casters. The base restriction was, no class with a cantrip. The players rightfully asked why I wanted such a strict restriction in the campaign and my answer was that I was trying to run a low magic campaign in 5e, where the party would be as close to a mundane party as 5e would allow. The players got on board with the concept and we went from there - I was specifically testing the system to see if you could do something and they agreed to test the system with me.
It turns out that 5e actually does work pretty well as a low magic game. Makes it far closer to a OSR game actually since healing is such an issue. As far as it went, the experiment was a success.
But, if DM's here are all about a "setting that makes sense" and that's their justification for restricting races, fair enough. But, it doesn't make a lot of sense to restrict races and then ignore classes. Now, if classes are also being restricted, fair enough. Otherwise it does seem a bit hypocritical to limit one and not the other.
DM: No, you cannot have a dragonborn in this town. They would freak out at that sight!
Players: Ok, well, my barbarian has yellow eagle eyes that are quite noticeable, the sorcerer has scales, the ranger has pixies crawling all over him and the rogue has ghosts floating around him. We walk into the bar.
DM: Well, you're all human, so, no problems.....