I know it has been 10 years; but for various reasons the Foundation still isn't 100% there on the organisational level. Particularly on things like communications.

The also spend a lot more than they probably should (for example; the budget for next year is something like $25 Million). That's not a criticism; things are still at the "investment" stage - where the Foundation/community are figuring out what to spend, where to spend it and how to do outreach.

So I don't think having ads, and a flood of money, would work well at this stage (or, rather, work effectively).

However; the biggest hurdle to ads on Wikipedia has nothing to do with perception or economics - it is simply that the community consistently rejects the idea. And the community has pretty strong autonomy :)