The system prevents new users from doing some actions until they have enough repution. One of these restrictions is the ability to comment on any other answers (needs 50+ reputation).
I frequently see comments posted as answers due to missing privileges. Seemingly new users want to contribute enough that they're willing to take the hurdle of creating an account in the first place and then notice they will need reputation points to proceed. That is however too much a hurdle and thus often an answer is posted instead of a comment.
To boot, those users' first impression is criticism from us for violating the rules. From the new user's perspective this may lead to frustration and some may immediately turn their back on this site.
It's discourage malign usage versus lower the entrance barrier for benign users. Our site is rather low volume and I have the strong impression that our user base is split in two halves: Questioners and answerers (who share their expertise). Often really good people are rather impatient with such things.
Would it be worth thinking about relaxing the comment everywhere privilege?
Or would this just drive up spam and moderator's work?
EDIT. Maybe this would be interesting to know:
What percentage and number of accounts has the ability to comment everywhere?