I'm fine with the basic idea (even though I don't like ads), but here are some concerns that either weren't adressed or didn't have a proposed solution:
Logistics: How many users are there that make significant contributions to the wiki? Is it plausible to do this as a solo dev?
Article Quality: As mentioned in the post, there is the risk of people spamming low quality articles for money. What is the solution here? Maybe a fixed amount for bigger contributors, but who falls into that category? Again: Logistics.
Trust: Since it was promised there won't be ads on the wiki, people may not react positively to this announcement, which might possibly be hurting the wiki. To be fair here, the process seems to be very transparent, though a forum to discuss about this would be nice, rather than just e-mail.