It's exactly the same for every Big Clubs in the world.
You can't be a Great Club, every seasons at the top level in Champion's League and Premier League .. and stay like a middle table Club of Premier League. The Club needed evolution to stay at the top level so we definitely needed a bigger stadium. Today, I don't know a Great European Club with a 40'000 stadium capacity (except Chelsea).
It's exactly the same for the rest .. football has changed, there's much more money involved in the game (tv rights, etc ...) and if a Club wants to stay at the top level, he needs to make some sacrifices, to get rid of a bit of the tradition in order to make more money.
BUT .. I agree for the shirt, there's no point changing the colours every seasons. They could still make new shirts every season but with the real Arsenal colours.
For the Logo, it's different, every Club has now a simplified logo because it's not only printed on the shirt and on the Stadium but in all sort of things. And it needs to be as simple as possible. That's the most important thing for any logo. I love the old one, I got the cannon from the old one tattooed on my arm, but it was a needed evolution. But They definitely should have done it differently.
I hope you get my point despite my poor english

The Club needed evolution, but it was a bit too much changes in a few years. The Club seems to be aware about that, they are trying to make the Emirates more like Arsenal's home, more traditional. I hope it's just a beginning.