Yeah, the issue being that Electrum is trying to support Lightning... which is where I believe the "expiry" time has more relevance. Unfortunately, this ends up being very confusing for new users who suddenly think their "receive address" is going to expire if their transaction doesn't confirm quickly (hence all the posts from users when the network is overloaded and transaction confirmation times for low fee transactions blow out to hours/days).
But maybe if they want to keep it, this feature should be moved to some sort of "advanced" section that has to be manually
Personally, I also like the idea of making it an "advanced" feature like with the "Pay" dialog and the advanced preview option... and I think it should be disabled by default (like the advanced preview).