Eh, the point of Mad Experiment isn't to destroy both players' facilities... that would be too powerful. The point is that you're giving up all your facilities on a risky gamble, hoping to get something useful that you can use to win. You don't get to use it immediately, though... so if the rare you just gave your opponent is something good, you may not even get a chance to use it. Not to mention the possibility of countering it with Black Market/Tribute... or, for that matter, Evolution/Micramix, which you may have just given them.
Odds are that most of the rares in your hand won't be applicable to your current situation; they're cards not in your deck, after all, so you'll definitely be getting cards whose abilities are limited by the random potpourri you've acquired. More importantly, you'll not be getting much more in the way of resources... at all... for the rest of the game. But if you've got enough resources already stockpiled, then it might be worth it.