Hm. When people actually say "I think Yahtzee should _________", I can't help but roll my eyes... they are entitled to their opinions I suppose, but frankly, they're being ridiculously egocentric, so file me with what looks like the majority of the folks above. About all I can add to it is this: he gets paid by the Escapist to generate pageviews, and likely has a contract to do so (which I bet prevents him from just abandoning ZP for a while because he's "tired"). If you feel that the quality of his work has gone down, then stop watching. If enough people agree with you and stop watching as well, then the people who pay him will notice, and may do something- like make him take a break- in an attempt to improve the quality of his videos. But other than that, you're pretty much TSOL. After all, you're not having your eyelids propped open with toothpicks and then being forced to watch, so it's not like you can do anything other than either complain fruitlessly (please don't) or stop participating.
OT: I have always felt that Yahtzee was inconsistent with the quality of his work, but I have yet to watch a video (and I've seen them all) where I thought to myself 'you know, absolutely nobody is going to find that funny.' So I keep watching. Some weeks, I barely crack a smile. Other weeks, I'm laughing so hard I'm crying. All and all, given that it's only 5 minutes of my time and it's free, I think it ends up being a good investment.
Honestly? I would say you should enjoy ZP while you can. I have a funny feeling that given Yahtzee now has several other means of supporting himself, when the contract is up, we may only see a ZP every two weeks, or once a month, or maybe not at all: it's pretty clear that while he enjoys the schtick, he would be a lot more selective about the games he would review if he could be.