Bigger venues are wising up to the WTS's tactics - they are finding out that JWs are being instructed to bring lunches from home and not utilize restaurants outside the venue, in an attempt to weasel out of having the added expense of concessions. They are also learning that JWs are being asked to pay for a parking voucher at the KH and the venue is being asked to provide free parking.
It's weaselly practices like these that get business people in a snit, and frankly, I think they're justified to be offended at these practices. The venues have agreed to their facilities being used for "charitable" purposes - and then the "charity" takes that generosity and tries to make a profit off of it.
Just because The Brothers™ go in and clean an arena before and after a convention, it doesn't excuse the underhanded practices of weaselling money out of people - both Worldly People™ and the JWs who attend the conventions. It would be a rare JW who would stand up against these practices if they were aware of them, but Worldly People™ won't put up with that kind of $h!t - they will refuse to deal with the WTS for future events, and who can blame them? Would you have repeat business with someone who intentionally ripped you off in the past?