Interesting, I've had the same objective and experience.
I currently seem to be on the naughty step, and I have been since August. It happened for a few days a month or so before - I've no idea what my misdemeanour was on either occasion, and whilst I might have been a bit forthright in some posts, I always sought to stay within the rules and never to be offensive to anyone on the board. Despite sending a message when I was able, to ask what I had done wrong, I never had any response. Now that my account is limited, I cannot send or receive private messages and my posts appear to need to be approved by someone before they appear, sometimes days later.
So, I'd had enough and I wanted to close my account, essentially to disappear from PPRuNe. As I can't send messages on PPRuNe, I tried e-mailing the head honcho at InternetBrands - it didn't bounce but I never got any response....and my account is still here..
Next try was to delete all my posts. This was interesting. I've been posting under this moniker for nearly 10 years and it was fascinating to look back over some of the exchanges that I got involved in, and some of the erudite characters who were good enough to spend their valuable time educating me and others with their expertise and, of course, the dry humour that I so much enjoy from some posters. It took a long time but I deleted most of my posts - not all of them, because, whilst my account is limited I am unable to post anything which includes a link.....and can't delete anything that contains a link either.
Despite what BoeingBoy writes, it is (or has been in the past) possible to delete an account. There was an occasion when the identity of those behind different usernames was publicly visible for a short while. I know of one account that was deleted, certainly as far any public viewer was concerned, after this leak because it could have been rather career-limiting if the true identity were to be matched to some of the posts. The posts remained but the Join date and location etc. were replaced by the word 'Guest'.
It seems a shame that aileron, who, like myself, has been part of this community for over 20 years, like myself, wants to leave. Whatever his/her reasons, it represents a huge amount of experience which will go missing. Probably more significantly for the owners, he/she is quite likely a pretty high-value potential customer for their advertisers - it puzzles me that no-one seems to care enough to enquire why anyone would want to leave. (Of course, the irony appears to be that it's actually a bit like Hotel California.)
I've been hanging around in the hope that my account will be made unlimited again so that I can, once again, try to get my account closed.....but this is the closest I've come.