If you set up something to collect donations for exDM69 they might have to explain to the police what was going on.
That takes time, and costs money.
exDM69 can avoid spending that time and money by asking you to stop collecting money for them.
And so now you have a choice: offer to give timy amounts of money to someone who will never accept it; or you could respect that person's wishes by not accepting donations for them. (And that's the honest thing to do for the people giving you the money! If Bob tells you he's never going to accept the money it's dishonest to keep accepting donations for Bob).
That takes time, and costs money.
exDM69 can avoid spending that time and money by asking you to stop collecting money for them.
And so now you have a choice: offer to give timy amounts of money to someone who will never accept it; or you could respect that person's wishes by not accepting donations for them. (And that's the honest thing to do for the people giving you the money! If Bob tells you he's never going to accept the money it's dishonest to keep accepting donations for Bob).