[inerte]

When you buy something you have some expectations. You'll want the mod to be stable, be updated along with the game, play along with other mods.

If you are the seller, and you got paid, that means work. Give support or get shouted at by dozens of angry customers. Reply to emails for months to come when a competitor modder added your mod features to his mod and why the hell are you charging 4.99 if it's worth 1.99 and now you need to refund your costumer.

Donations, on the other hand... explicit intent and different expectations from everyone involved.

Also, it might be neither "most don't want to be paid" nor "most want donation", and both sets might have a very small intersection.

[belorn]

Donations normally also happens after someone has used the work, rather than upfront.

[_lce0]

plus that the seller requires to set a price, which may be too high/low .. but using donations happy customers can pay whatever they feel is ok for them