I don't dislike Jimmy Wales. "Please donate to Wikipedia" is one of the most common "please donate" type messages, and at least in the past it was usually written from the first person with a picture of Jimmy Wales' (usually unshaven) mug. It's just a joke. Nothing more.
Wikipedia used to have this huge banner with the cofounder staring right at you as if making eye contact[1]. Inevitably, it became a meme for a time with other people seeking donations creating graphics mimicking the original.
It's not for Jimmy Wales specifically, HN just tends to have a kneejerk reaction towards any NGOs asking for money. Mozilla, Wikimedia, Gnome, FSF, Creative Commons, it really doesn't matter. Any thread even tangentially related to such orgs is always met with dozens of comments where people go out of their way to either justify not donating, or saying how they used to donate but stopped because of X, Y and Z.
The only exception to the rule is the Internet Archive.