Can't help you. If you want to watch same content in over 10 channels. It would help the viewers if channels starts providing closed captioning and multiple language feeds instead of launching channel after channels every year.
And about bandwidth. Almost all broadcasters are indeed wasting bandwidth. What's stopping them from switching to HD only? Ask DPO's to slowly downgrade for SD users. Most have been in simulcast mode since NTO. I don't see any difference in content or ads. Tata Sky as a sensible operator have starting to hide channels which are simulcasting after purchase of the SD channel or it's HD counterpart.
Not possible for most chs to have just HD feed. Multiple reasons which i have earlier discuss in detail. Till SD boxes r major part of connections both feeds for popular chs will continue. Niche chs can have single feed and downscale for SD as target audience is small, for regular channels advertisers have separate budget for reaching mass and affluent audience