if you're going to use TT for 2021 why don't you just buy the software for 2021?
or download the extension from te IRS website and paper file.
also, some people might get confused and rather than filing for the current year accidentally file for the next year and not find out until it's too late that they don't have a valid extension. if they included payment then they have to go through the trouble of having to contact the iRS to move the payment.
if another app offers this convenience, why not switch? probably because other apps don't do it either.
