51 inch 720p plasma? What's the point?

So I recently saw the prices of Samsung's 2012 lineup posted here

I am currently looking for a 40" full HD TV for price around $800,

however 51" plasma TV resolution 1024 x 768 is available for the same price!

So does it make sense to buy a larger lower-res TV here?

Also, its aspect ratio is 4:3, doesn't that mean black bands above and below or cropped picture?

So is there any point in buying a 51" 4:3 (around) 720p TV instead of 40" 16:9 LED 1080p TV?