I wished they had broken everything harder and once and for all, in order to fix the issue.
If there's going to be breakage anyway, people adjust their expectations. The scale is basically:
a lot of breakage > a bit of breakage >>>>>> no breakage.
Once you do break backwards compatibility, you might as well do it in a big way, provided you:
* don't offer vaporware for a decade (hello Perl 6!)
* try to offer some mitigations for the migration pain (auto-conversions, support libraries, top-notch docs, etc.)
* offer a great carrot at the end of the tunnel (good performance would be such a carrot)