i ALWAYS have the tv on. i grew up with it on and it remains on. both of my kids are used to having it on, although they can go long stretches without it. my kids don't turn into vegetables in front of it, though. if they did, i'd be turning it off a lot more. my kids keep playing and running around. they only stop to watch for a few minutes at a time. they watch a lot of disney playhouse, which is great. it plays mostly learning shows and my kids have learned a lot of stuff from them. my son learned a lot of phonics from watching WORD WORLD. of course, i've emphasised it at home as well, but he's really figured out how it all works with little input from me. he now can sound out hundreds of words and put them all together to know what they say.
i think your husband is over reacting a little. i also think he's not had to entertain a toddler for more than a few hours at a time on his own and may not understand your need for a bit of a break...
tv is a very personal decision and no one is right or wrong. it's all a very subjective thing and we each make decisions to suit our own needs.
good luck!