It might be the case these advertisements allow PPRuNe to function in the black. However if it may operate with the income purely from the recruitment agencies, headset manufacturers and James Bond gadgets.
This site does have hosting costs and other overheads after all.
Publishing organisations have slightly less scruples and I can't see them stopping them.
I would hope as this site was founded by pilots and generally moderated by them that its something going forward they would at least consider.
Advertising on here gives them a degree of credibility (I use the term loosely) despite the overwhelming objection to the practice on the threads.
However, you then move into the "why not, they'd just spend their money elsewhere, so why not take their money" debate. I also doubt they would cease their slimey trade due to lack of advertising on PPRuNe.