… is that really the best way to prevent spam on a site?
I'm afraid it is, yes.
I understand the frustration and it can feel pretty backwards when it's getting between you and doing something good, but as somebody who has seen systems without these checks in place, the level of spam we're talking about stopping is almost unimaginable.
You also need to understand that this site runs on the time and sweat of its community. This is a very finite resource and we need to spend it carefully.
- Questions and answers from new users are manually reviewed by 3-5 people
- These (and other reviews) generate flags that also get reviewed.
- Flagged issues also go can go up to one of a handful of moderators
- We ask users to edit and improve any post they can
- As well as voting, to help distinguish better questions and answers.
- And that's all before using their expertise to actually help people with their problems. Reviewers get to be reviewers by having reputation.
On a question and answer site, comments are merely an occasional-but-necessary evil, a lubricant to help questions and answers get better. But given we're already splitting our users time between answering questions and fixing bad ones, reviewing what would-be thousands of comments —many of them "thanks" and "+1", and even more flagrant spam— I think keeping some focus on the questions and answers isn't a bad thing.
You can see more about privileges here: https://askubuntu.com/help/privileges
You're really very welcome here, Chris, but there are differences between this and a forum. I believe those changes and quirks are what makes it effective.