Having been thoroughly moderated by Toady and ThreeToe, I'll say this. They don't like enforcing the rules. They don't like angering forumgoers. Every warning, mute and ban they dish out has a negative consequences to them. They lose community members. They lose a donator. They lose a little magical sunshine that is a place where everyone gets along. But they have to make tough decisions.
Do you think they want your dog to die? Of course not.
Do they want you to have the money to help him? Of course they do.
Do they wish you could get that money? Naturally.
The problem is that they can't allow others soliciting donations on the forums that they use to solicit donations. If people started raising money for textbooks, charity causes, or political canidates the people who come here with a fresh paycheck in hand will see a half-dozen threads asking for money, all worthy causes for sure, but meanwhile Toady hasn't put out a release lately. Well if someone donated for last release and had money to donate, which would they choose, curing cancer or Toady's water bill? Furthermore, what would happen if someone took the money and ran? False donations and donation schemes are rife on the internet, and Toady and ThreeToe can't police that sort of thing, even if they did have time.
So it is reasonable that other donation drives not be allowed. This rule can't be bent because you have an emotional appeal, all donation runs are on emotional appeals. Your dying puppy, I hate to say, is far less worthy than the thousands of charities for dying people. If he allowed your puppy, he would have to allow everything else or be a hypocrite.
I would sooner the rules be unbroken than exceptions allowed and the rules to become inconsistant, so I must support Toady and ThreeToe in this.