What is the problem?
I'm going to assume you're genuinely looking for an explanation. If you simply want to express your frustration, it would be best to post it here:
https://itch.io/board/10017/general-discussion
But since you're posting in "Questions & Support," I assume you want to know a bit about the reason.
I also want to clarify that I'm only explaining the reason we've seen; I'm neither defending nor attacking your position, just explaining the facts.
Several months ago, there was a surge in comments with malicious links on Itch's game pages. Every day, this forum was flooded with people complaining that Itch wasn't doing anything to prevent these comments with malicious links on legitimate sites. What we know is that some of these links were designed to trick people into downloading malware onto their computers so that their credentials could be stolen, so it was crucial to prevent it.
The staff should have implemented a filter, which unfortunately catches many legitimate posts. (False positives) And now, if you check this forum, you won't see posts from people complaining about malicious links, but you will see many posts from people complaining that they can't post.
Basically, we went from a system that failed to detect fraudulent posts to one that is capturing too many false positives.
Please note that I am explaining the events; I am not discussing how effective it is or whether it is the best or worst system.