For what it's worth, Charity Navigator gives them 4 out of 4 stars with a 98.33/100 rating: https://www.charitynavigator.org/ein/200049703
Meanwhile eg the American Cancer Society gets 73/100 and spends more on fundraising than WMF's entire budget, so oncologists can snort blow off hookers in Vegas, but nobody cares.
It's a bit of a self-defeating attitude. Hackers love scrappy upstarts. Succeed too hard and you cease to be a scrappy upstart.
Wikipedia's current ads are both misleading and more intrusive than ever.
550 employees is huge, especially for an organization that doesn't even pay those employees to create and edit the content on the site. It's so far away from "on the edge of pauper" that the point you're making—even if true for other, non-Wikimedia realms—is completely irrelevant here.
I will sooner give $20 to someone begging who tells me that he intends on spending it on booze, than I would a well meaning non-profit who attempts to snow me with rhetoric honed on manipulating millions of other people before me.