First off: Didn't Guitar Hero come first, which lead to the OG developing team behind that moving on to Rock Band after the second(?) game in the GH series?
Yes. Harmonix developed Guitar Hero, Guitar Hero 2, and Guitar Hero: Rocks the 80's, published by RedOctane. Activision bought RedOctane and the IP rights but figured they didn't need Harmonix anymore and let them go. They put Neversoft on the succeeding games, and now Freestyle Games is at the helm. Harmonix went to MTV Games/ Viacom and pitched Rock Band. The rest is history.
Second off: Is it still worth getting on the Wii U due to a lack of a Rack Band alternative?
As someone who is a MASSIVE Harmonix and Rock Band fanboy, and who was actively boycotting Guitar Hero since 2008, I decided to break my boycott and buy this game, and I'm having a pretty good time with it. If you can get over the ridiculously campy FMV videos, lack of ability to actually own DLC for the game, lack of hyperspeed options, and a sometimes difficult to read charting style and hammer-on system (hammer ons are marked by highlighting the outside of the note in almost the same colour of blue used to mark star power sections making the two almost indistinguishable especially when they overlap), it's a pretty fun game so far. It's worth noting though that this game ONLY has Guitar and vocals, none of the other instruments that the series has had since they copied Rock Band.
If all that I've said so far hasn't turned you off of the game, then give it a shot. The GH:TV setlist is huge (~200 songs) and pretty varied and balanced with lots of memorable hits.
Third off: The lack of a "sweet spot" intrigues me the more I think about it...
I think that this game does quite a few things well, but blunders on several others. If they can clean up their charting somehow, especially the hammer on system, it will make things a lot better.
This is a game that from the ground up is fundamentally different than all Guitar Hero and Rock Bands before it...
It's a surprisingly innovative title...
The biggest change in Guitar Hero: Live is its guitar peripheral, which now has six buttons
Um, this is a joke, right? This is an incredibly innovative game fundamentally different from everything that came before it, and the biggest difference is that the pretend guitar has a slightly different button layout.
It may seem like a simple change, but it changes the way you have to think about fretting notes in a very significant way. It may just be clumsy charting sometimes, but the new system has a way of fucking with my head and having the 2x3 layout makes new combinations possible that weren't before, like barre chords, and having to make semi-realistic chord fingerings. You have to re-learn a lot of what you mastered even if you are a seasoned plastic guitar warrior.
Also, having an extra button makes this technically more complex than other games even without the new layout.