Hm...this is a bit hard to explain. Especially since you weren't that much over the top. What did you do wrong, you ask? What do we expect of you? Which is actually a good thing to ask when you're partly in the hot seat from official rules and standards, and partly for unwritten rules and standards, so I'll try to add to what they said above.
First off, like they said...we're a support forum. We also were once specifically a teen forum, which means the focus is still more towards the younger bunch, and we actually strive to be teen safe, teen friendly. Even on the adult baby forum, everything must be PG - 13. The mature topics forums do have more kink related material, but even then, it can't be explicit. This means anything we think would be a bad idea for teens to do, we actively discourage. Coming from other sites, where there are plenty of weirdos, perverts, predators, crazies, and downright stupid people, teens see all sorts of various crazy and stupid behaviors and discussion all the time...and get the impression that in the ABDL world, this is simply how you act. We want to encourage them to be safe and sane, so we try very hard to not let topics displaying that sort of behavior on here. So yes, we are quite trigger happy to attack anything that is a bit out there. And well...from a health point of view, what your topic talked about was fairly iffy, from a common sense and sanity point of view....I can easily have trouble believing it, and am not surprised everyone else though you must be making it up too.
Second, We pride ourselves on having intelligent and mature discussion. We prefer having members who can talk about more than just diapers, and we encourage them to contribute discussion about all aspects of themselves on here. This also means that anyone who joins, and immediately just wants to talk about diapers, or the more extreme aspects of ABDL, is seen as possibly someone we don't want here. The preferred and encouraged way to start chatting with us is to make an introductory topic on the greetings forum, telling us a little about yourself (and hopefully more than "omg i luv diapees they r so grat an im 14 an in schol"). After that, just reading around the forum for a day, making posts in topics where you can, so people can get a feel for who you are...once we get to know and trust you a little, making topics that are a little out there is much more easy to swallow.
PS: for a wonderful lesson in what we don't want here, read this recent topic
http://www.adisc.org/forum/greetings-introductions/3447-i-don-t-under-stand.html#post60763
and related profile:
http://www.adisc.org/forum/members/babozjam.html
As you can see...people are quick to attack posts that sound like yours...because when they show up on the forum, they're often just fake. Note that the person who made the topic was banned hours later, for lying about his age in his profile. Most members here are fairly good at spotting this sort of thing. Problems just occur when someone comes on, and one of their first few posts is talking about their highly unlikely life...and it's true. It's a little hard to believe sometimes, especially if we just met the person.