Certainly when it comes to Wikipedia: there is oversight. I know people don't like the fact that Wikipedia spends money on things other than server racks, but spending money on developing the community is a pretty legitimate thing to do! How else can you maintain such an encylopedia? You need to attract knowledgeable people to write and review articles!
The objections are primarily around the aggressive and deceptive fundraising.
Wikipedia collects donations by essentially saying (in some years more directly, otherwise more implying) "if you don't donate Wikipedia WILL DIE", rather than "Please give us some money so we can build an even bigger community to make Wikipedia even better".
They are also making the banners incredibly obnoxious. From "donate or ask later", full-screen interstitials, to delayed popups that interrupt you after you've started reading, and with increasing frequency. During their "yearly" fundraisers (I think it's actually 2-3x a year, masked behind "local" vs. "global" campaigns) they pop them up every few days on every device you use, and now they're introducing "experimental" banners every month (again per device) so several times per month, and more frequently if they delete cookies. [1]
[1] https://meta.wikimedia.org/wiki/Talk:Fundraising#Proposed_ch...
It's also obscenely disingenuous to ask for donations like they do with this current model. Downright insulting.