That's kind of sad for your TV. Apple uses industry standard H.264/MPEG-4 AVC, not the Microsoft proprietary WMV or AVI. Complain that your TV can't do industry-standard formats.
BTW, changing the file extension to something your TV recognizes might work if it can indeed handle the underlying codec. It could be that it doesn't, because H.264 requires some serious computing power to decode (and more to encode), but that's why it gives the best quality for size.
My TV will decode full 1080p hidef H.264/MPEG-4 video streams. AVI, WMV and MKV are just containers for the video. It plays industry standard formats just fine.
iTunes uses industry standard MPEG4 video but puts it in a container that nothing but their players will play which makes them more proprietary than WMV and AVI. Even my 8 year old plain jane DVD player will play AVI files.
Changing the extension will not let you play Apple video on a non apple device by design. They designed a closed system. If you want to play iTunes video, you need an Apple sanctioned device.
From what I see, if you want to play iTunes video on your TV, they want you to buy one of those apple TV devices (which isn’t even capable of playing 1080p video) or a Mac Mini to connect to the TV. That makes that video pretty darn expensive. A TV out on the iPad would make it much more useful to the person loading all of their favorite shows in hidef.
Come on, you can’t admit that letting you connect the iPad to a TV might be just a little useful? Seriously are you just arguing for arguments sake?