The point is that they should be rewarded for making a damn good game.

True. I think the "There's a zombie on your lawn..." music video actually helped sell me on the game during those milliseconds of indecision when I was still unsure as to whether or not I was actually going to purchase it.

Okay point me to the single best video of the gameplay, an avatar of this alleged awesome and I'll give it another look

Point me to the single best video, that explains the addictiveness of Tetris - you can't. Some games just don't show why you like them in a video. Plants vs Zombies is one of them.
If all the guys claiming it to be worth your attention didn't convince you to give it a shot until now, probably nothing will. This however, would be completely your loss. :)
"singing" there's a Zombie on your lawn.... there's a Zombie on your lawn.

You either like it or you don't. If the demo didn't sway you then perhaps it's just not your thing.

Aliasalpha, I was once like you. One of my coworkers was really into PvZ, and wasted no chance to laud its merits to me. I, for one, thought it looked and sounded pointless and stupid, and pretty much refused to have anything to do with it.
But then I had the opportunity to try it out for myself... And I was an instant convert.
So give it a go. Spend five minutes to form your own opinion. If you still don't like it, fine. But try it out.

It's a variation on tower defense, these things never look fun even though they're fun to play.
Seriously, the game's gotten nothing but positive reviews from both critics and players, so I don't know why you're surprised that people are saying it's good. It's not like it's an underdog that a couple people are supporting or anything, so it's kind of odd that you're so incredulous.

Except for the fact that for most of the game, it's just playing the same one-dimensional game 5 times at once, PVZ is incredible. It's definitely worth the $10.

So true. I am glad I decided to give Defense Grid a try, it almost immediately became my favorite game of all time, a position it still occupies.