It’s not a question of whether you like it or not, the problem is that it breaks the design of existing sites – because their themes are using bp-default as a ‘much touted future proof’ parent theme.
You expect bug and compatibility fixes in a theme upgrade, not presentation and design changes.
If you’re changing the actual design, you’d expect that in a new theme. Much as you’ll expect WordPress to release 2011, and not simply overwrite 2010 with something different that changes the look of every child theme based on it.
