The question you're referred to has been protected due lot of drive-by "answers" which doesn't really answer the question but are some sort of "I have this too" or "this is sucks" posts which the answer section isn't really meant for.
Clicking on the Highly active question tells you why it was protected. You need 10 points, not 50 - you can earn rep by answering posts, suggesting edits etc - 10 rep is not that big of a number, tbh.
The 50 rep requirement is for posting comments - comments aren't meant to be answers but rather ephemeral clarifications or notes that are bound to be removed at any point.
So the point is, how can you post an answer on SuperUser to let other people in on the answer, that has clearly been troubling people for years and (based on early comments) is actually now much worse than it was when the question was first raised. (ie buttons used to exist, but were greyed out. Now they don't even exist)
This doesn't seem like an answer, at max a comment which doesn't really help in any way. As an answer it'd most likely get flagged as not an answer (and precisely why the question was protected in the first place - to prevent non-answers from being posted)