Actually...some TVs you can. ; My hi-def Mitsubishi has manual adjustments for color tuning on 3 different bands, contrast, brightness, luminance, tone, B&W points, etc, along with a standard color bar/focus/black and white scale test page. ; The Spyder can't talk to it and make adjustments, but a good eye and some practice can.
That said, 1080i doesn't quite match up resolution-wise with a decent 1920 monitor...and considering how much larger the TV often is (65" in my case), I'd need 10x that resolution to have it look as sharp and pixel-free, or have to sit 20 feet away! ; I love viewing slideshows on the big screen for friends and family...but I wouldn't edit off it.