"important" is a per-person individual decision.
A phrase that used to be very common is "mechanism, not policy".
The role of a vendor is supposed to be to enable mechanisms so that customers can implement whichever policy that best fits their needs.
The role of a customer is to choose and implement the policy that best works for them personally, using the mechanisms that the vendor provides.
It is fundamentally wrong for a vendor to impose policy, that's not their job. Nor do they have the information to correctly make that decision.
Some (few) people have important source code in their github account. I'd highly encourage those people to enable 2FA. Most people don't have anything important that anyone else uses, so adding the overhead of 2FA for them is beyond silly and purely obnoxious.