It's probably because they are personal appeals. These employees are asking for donations to Wikipedia, claiming it comes from them. So they are begging, not Wikipedia.
Wikipedia asks those employees to make "personal appeals" when they're running low on cash, then dedicates almost every single page on their site to asking for money.
Wikipedia is a nice site and deserves the cash, but it doesn't change the fact that they're internet begging and refuse to admit it for whatever reason.
I've used wikipedia SO MUCH. Like, 10 bucks for the past 10 years of use? Thats a steal.
And I think "begging" and "asking" are two totally different things. Even if begging has become a term for requesting online donations, its derogatory, and wikipedia doesn't deserve that IMO.