[gnat]

No, more a function of businesses having obligations not to waste their shareholders' money. By definition, donations are optional things. A donation be heavily questioned afterward if it is allowed to go through at all. But buying marketing, or support, is a perfectly sensible thing for a business to do.

[r_smart]

So what you're saying is, the people currently using the software don't have control over the purse strings?

[PeterisP]

No, the point is that for many companies noone, including the people with as much control over the purse strings as they can have, is allowed to simply donate money to something. It's not that you need permission from someone to do it, but that for even the top decisionmakers donations as such are not a legally permissible choice unless you can credibly justify it as not really a voluntary donation but buying something of value to the company e.g. marketing.