Being a steady fan of a couple of series I do enjoy the familiarity with new things added, I also enjoy innovation. It mostly depends on the execution of the game. I'm mainly a casual gamer, but I do have those occasional several hour sessions of being glued to a game.
A fairly recent experience in innovation vs familiarity was Hometown Story, a game from the Harvest Moon series. Except there you ran a store instead of having a farm. It would've been a really great game if not for a huge issue for me: The movement controls were seriously bad, so bad you were pretty much locked to the store you ran like a show seal being told to do tricks all the time. It was frustrating enough that I gave it up. I would've enjoyed the game mechanics too had the controls been better, but nope, immersion broken while trying to close the store early and not finding a way out.
On the flip side, the same company released a new game about 6-7 years back called Rune Factory. They didn't intend on marketing it as related to the Harvest Moon series, but it got marketed like that for the English translation. It's basically Harvest Moon in a fantasy world where you tame monsters instead of buying animals. Plus you got dungeons, weapons and magic!
It's a well done series to say it simply, considering that they've released at least four more games in the series...
My point is: Innovation and newness counts for nothing if the game is bad enough to ruin the immersion/enjoyment of the game.
Similarly is the game mechanics, tossing anyone into having to learn something completely new just to have fun can make some people get a little prissy. Or a lot. Especially when they favor the older games.
At a previous forum (a FF fans forum) I spent time on they absolutely loved Sephiroth to bits and enjoyed hating on FF X-2 for being "a girly preteen game". -.- I like that game. It's not legendarily innovative, but it did have a battle system that changed things up and the ability to change jobs in battle without taking away the need for tactics.
Yes, I consider those guys prissy (plus a few other things), but not just for that reason. While they were busy ranting about it being a girly game "designed to bring preteen girls into the series" I was busy playing it and testing out the new mechanics. New things are scary, so people latch onto the old and familiar, the safety of what they know. They can talk the talk about innovation, but braving out to take the walk is something completely different. Humans are creatures of habit in the end.