A faster and smaller default system shell is important to a lot of our
users.
I see this asserted a lot. I am pretty sure that the average
user very likely does not care. The embedded system folks certainly do
--- but I am not sure that the counter assertion that systems will
break if /bin/sh is changed under them do not equal in number the
people who benefit from small default system shell.
I think it is OK to start with dash as the default on new
installations, and to ask if people want to switch older ones. Forcing
the switch would be, in my opinion, buggy behaviour.
Pardon me if forcing the /bin/sh to point to dash on existing
machines is not the plan.