The nature of a competition is that if cover art is removed, something else will take its place – blurbs, probably. If you remove the blurb, things will get judged initially on tags and titles. You could keep going until all games are given a number ID and a link and no other context, but why?
As someone who’s entered IFComp before and is (hopefully) entering again this year, I’m not terribly worried about the cover art affecting anything. The entries live and die on the content of the actual games, and if you have a good game then good cover art will, at best, get it looked at sooner. The strong reviewing culture around the Comp plus the long window for judging means that good games will get traction based on word of mouth eventually.
There’s always time for more in game development – more polish, more rewrites, more bug-fixing, more little details. If someone (me) is up at 3am the night before the deadline working on any aspect of the game then that’s a time management issue, regardless of what you’re doing? At least we weren’t removing game breaking bugs at 3am! That was Lady Thalia 2