3.6 extra inches of clearance for the Crosstrek vs. the Impreza is a lot more than the 1 here though. I think that's part of the complaint.

The Crosstrek also gets a beefier rear diff, stiffer suspension, and larger brakes too.

They're the same platform, and share a lot of bodywork, but that's not uncommon among manufacturers now. The Golf and Atlas are both on VW's MQB platform now but that's about where the comparisons end.