It appears that their biggest expense is the $38,597,407 in salaries distributed to ~350 employees. This makes the average salary $110,278 at the Wikimedia Foundation. I don't really have anything negative to say about that.
However I guess you could question why they need 350 employees. So I looked at the projects they are currently working on:
https://meta.wikimedia.org/wiki/Complete_list_of_Wikimedia_p...
Reduced spending and reduced donations would be a good outcome for Wikipedia readers (especially in the long term). Lower running costs allows putting more current revenue towards that endowment, and means the future is a bit more sustainable in less favorable economic cycles.
Donations also don't exist in a vacuum; the best use of donors' limited money is probably not WMF burning a pile of it.
I'd encourage, for example, https://www.givewell.org/charities/top-charities in place of WMF giving.
The worst part of it for me is that they advertise it on Wikipedia as if wikipedia were going out of business. When in reality, if you give $1.00 to WMF, ~$0.03 goes to server expenses. Wikipedia is their cash cow that funds a ton of random pet projects and a dozen or so executive staff (which seems huge for a 300 person organization).
If they were honest about that in their fundraising, I think they'd see flat or down revenue. I dislike the dishonesty used to solicit donations and then use them somewhere else. It feels similar to a con.