I don't think I think a core critique of 37S should be because they are 'opinionated,' but rather because they are spread too thin. Would be better to focus on fewer webapps and respond better to customer interest. I'm sure I'm not alone in saying that I have stopped using Basecamp because much of the attached and desired functionality is simply not there.
I've stopped using Basecamp as well as it lacked some necessary features and it didn't look like they would come anytime soon. On the other hand there seem to be enough people that love the current product otherwise 37S wouldn't be making money.
