If you really want to get it, keep reading. If you're likely to take offense, please skip this reply.
It's a matter of HOW you voice your opinion.
The way I see it, accusations of "Stocking Police" (which are meant to be humorous, not to offend or insult) are likely to come when someone makes a statement about stocking levels or overstocking as if it's a dead set fact, carved in stone, with no possible exceptions whatsoever, such as "Dempseys need a 55 gallon all to themselves, just so you know." To be perfectly honest, it also sounded a bit condescending, IMO.
It may not seem like a big thing to you, but if you were to simply change how you state your opinion, it would make a big difference. Say you said something like "A 55g (may be a bit, might end up being, could be, etc. take your pick...) too small for a Dempsey with other tankmates. Then you've simply stated your opinion, the person you're offering the advice to can still take it into consideration, but you don't sound like you're saying it's impossible for things to work out any other way.
Either way, you're making the same point, but there's a big difference in how your statement comes off, especially to those who have personal experiences (sometimes decades worth) that vary from your own, or from what your online research has taught you.
I'm not trying to come off as a jerk, you just seemed genuinely concerned, and I thought I'd offer my viewpoint.
