I disagree in one way, but agree in another. It's one day in 365, it provides a little bit of relief.
But, of course, there are a lot of lame jokes. Just like there are a lot of lame news articles that could potentially be posted on the site but are not upvoted.
So why don't we optimise the SNR, and only upvote good April Fools pranks?
I think that's a good compromise.