Tech TV had a purpose, had a niche. G4 sadly had a nich that was already being filled on the internet. Thus, to become profitable, they completely changed their channel to show cheap re-runs and imports.
Even though TechTv wasn't my thing, it could have actually succeeded at its original goal, G4 was doomed to fail because they were trying to do the wrong things with it. If they would have put a focus on a more select group, if they would have done things like broadcast Evo finals instead of pandering towards the more general gamers but brought something new to Video Game news industry, they could have succeeded, but sadly, they brought nothing new, and if it were not for Morgen Web, I don't think they would have an original show left.
In fact, look at X-Play. It was oddly enough NOT a very news based show, they knew they couldn't compete with Gamespot, IGN, Kotaku, etc. in terms of giving people what they wanted in terms of reviews, so they went the Angry Video Game nerd route, except with some very, very light plot and reoccurring themes. Once they became a straight news show though, I stopped watching.