Even if you opt-out of MFA, the next time you try to log in, it requires you to use MFA. Why offer the opt-out option if you are forced to use MFA?
Here is the blog:
Basically it’s a security measure.
People can be lazy or sloppy and use same password in multiple services and when one of them has a leak, then all of them can be affected.
The main problem is, that if your developer account is “hacked”, the hacker can release updated addon and then all users of your addons are hacked!
2FA fixes that 