And we still require it. Some things change... while other's...
As for the OP, if you send traffic that's (and I apologize but..) so low quality that a banner on a footer of a tour ends up being seriously detrimental to your business... well... you really don't have quality traffic, do you? :P
It's not easy running a program these days. We've seen so many sponsors folding--not because they have made so many gold bricks and wish to retire early, but because it's tougher than ever for smaller companies to gain traction.
We have a perfect filter. Instead of trial and error, throwing up banners on a tour or member's area trying 10s or 100's of sponsors, we can do it with a thousand sponsors immediately. We optimize so a sponsor can make the most of crap tour traffic or killer member's area traffic. We've been doing this for a decade so we know what we're doing.
We don't make a ton from it, but the sponsor usually can make more using us than anyone else just due to the amount of options we offer and our ability to optimize. And you, as an affiliate, should let them.
If you really have quality traffic and you're sending a bunch of valuable joins, then the sponsor may not mind doing a custom tour for you, one that's clean and without our ad system. You should always ask. Short of that, we all should be lucky that whatever sponsor we're sending to is still in business and allowing us as an industry to make money with them. It's really tough out there and everyone deserves the right to survive. That goes for you, us and them.
And StinkyPink is right. All affiliate traffic should go to your home page and not the warning page. Leave that for site's like ours that require a recip. It's just smart business.