Hi Sam,
Thanks for the response. I tried to make a feature topic but it was locked and going to be deleted, I didn’t think it would be considered a duplicate as there do not appear to be other feature request threads specifically about this. There are several support posts asking how to edit the robots.txt file.
Here is the post I made specifically for this:
https://meta.discourse.org/t/robots-txt-remove-blocking-user-profiles-or-allow-editing/94082
I searched for a relevant thread and thought that this was the second thread being referenced as the reason for closing the topic. My apologies. Having a way to edit the robots.txt as the title of this thread says, would solve indexing issues for everyone 
Ok understood, most of the arguments for excluding the user profiles I’ve seen are mainly for SEO, duplicate content etc. which I don’t agree with. I didn’t see people not wanting their profiles indexed on a public forum as one of the primary reasons to exclude them, it is a valid reason, just I don’t think it was part of the decision making process (at least publicly) when they were originally removed: Excluding user profiles in robots.txt (or allow edit of file)
I’ll stop posting in this thread now anyhow. Thank you.