Deciding what to do for everyone based on what some folks complain about isn’t always the best practice. If those complaints tended to be completely valid, and suggested an overall issue with a 90% default DR (or an issue with the algorithm), that would be one thing.
But most of the generic intervals-are-too-long complaints I’ve seen are about (a) the user needing to adjust to how much better/more efficient FSRS is at scheduling – i.e. intervals can be longer, but maintain retention – or (b) revealing some other issue in the user’s collection – which needs more investigation (sometimes also resulting in bug fixes, which benefit everyone), and might be partially masked by a higher default DR.