Exactly. How about not losing scroll position when switching tabs? Better spam filtering? How come threaded view doesn't work for mails sent by Outlook? (I know we have Microsoft to blame for that, but a workaround should not be impossible to conceive since Outlook somehow manages that already.)
I suspect the people getting excited about a face-lift don't really use Thunderbird very often.
One has to be a coder, able to deal with the current state of code and the many changes to come, while having a load of free time to maintain the fork.
I mean my 90 years old grandma is a decade long thunderbird user and she absolutely unable to make thunderbird the way she wants. She is 100% dependent on mozilla's good will.
I suspect the people getting excited about a face-lift don't really use Thunderbird very often.