I have observed in multiple contexts that users generally don't like change.
There are probably several reasons for this:
* understanding change requires mental effort
* users have already evaluated your service once and don't want to keep reevaluating it
* users bring their physical world expectations online (e.g., imagine buying a sports car that is then transformed at some point into a family car because the manufacturer decided it would be a good idea)
I think that, at least during a startup's early-adopter stage, the userbase is comprised of exactly the people who thrive on change (especially change for the better), so even if your hypothesis is correct, you may have a window of opportunity to make some aggressive improvements.
There are probably several reasons for this:
* understanding change requires mental effort
* users have already evaluated your service once and don't want to keep reevaluating it
* users bring their physical world expectations online (e.g., imagine buying a sports car that is then transformed at some point into a family car because the manufacturer decided it would be a good idea)