Honest question that might come off as stupid but, doesn't CERN have a huge budget? I imagine supporting this project can be a reasonable budget entry, why are they asking for donations?
CERN's budget is ~1B USD, which is 5% of NASA's, 25% of ESA's. And I won't even get started with Silicon Valley big corps.
Considering you have to pay for an electricity bill equivalent to 1/3 of Geneva and the salaries of >3000 people in one of Europe's most expensive urban areas, I wouldn't say there's a lot of money left to invest in pretty much anything.
The CERN budget is split over multiple projects. Also, budget + donations > budget. Lastly, by opening this up for contributions more people can feel part of the push for improvements to KiCad.