I'm not sure why the average opinion changed like that (maybe because 2FA on SMF became such an unlikely idea that people started "defending" the lack of it?), but I align with the more optimistic group and think that a correctly implemented TOTP option makes a ton of sense (even for SMF).
Did some people actually defending the lack of extra security for their account? I mean why? if they don't want it they can just turn it off, but it always good to have an option.
I read the whole OP post, several times, but I didn't find what type of 2FA would be implemented, will it be Email based, or using 3rd party App, or mobile messaging. The least effort might be Email since we already registered our email in this forum, but wouldn't it be less effective since most of the hacked account got their email hacked too? I mean if the account is hacked and the email is not hacked, than we could just use 'Forgot Password' to recover the account,