If you think that is wrong then you would have to criticize theymos too, what you surely won't do, but the forum is auctioning adspace so the connection to the advertising company is not much different.
You realize that you wear a signature that pays you too? The only difference is that you can fully back that company. I only can do a slight check, though that is the same with theymos.
First off, theymos runs this community. He sells space here for the service that is provided. Members getting paid to advertise to this community using this community is not the same. If theymos is a manure salesman, that doesn't give you the right to get paid to shit in his customer's yard. That is another topic though.
Secondly, I don't advertise a company. I advertise my safe escrow services for this community, cool coins I make which I donate nearly all proceeds to NastyFans, and my NastyMining thread that I HAVE DONATED TIME AND FREE ELECTRICITY TO FOR NEARLY FOUR YEARS. I love Bitcoin and I think what I'm doing is cool and honest so I try and make it known.
Please don't put our actions in the same category.