The thing is that it's not the job of some minimum wage ticket-takers to enforce the Health and Safety Code of the State of Texas. Now that all indoor venues are smoke free, it is there job to enforce smoking bans, regardless of what's being smoked. Some places are more stringent than others. Personally, I think it's pretty silly.
On a side note, I'm probably one of the only people to ever light one up in the
crown jewel of Fort Worth. Took about 45 seconds before a maglite was shining in my eyes from one of the ushers. After the show I somewhat sarcastically asked her if she took her job seriously enough. She replied that they take that building very seriously. Damn fine answer, actually, for which I commended her. They have a very keen interest in making sure that stoned Tull fans don't burn holes in their seats, and she was right to single me out.
That said, there's a big difference between those types of venues and the arenas that Waters is playing. There's going to be a significant difference in the amount of acceptable wear and tear on the venue. But again, it has nothing to do with wear and tear, and everything to do with living in a city wear smokers are seen as evil scum. One's a reasonable notion and the other's bullshit.
And then there's the practical approach to the whole thing, which is that I stopped caring about opening bands a long time ago. Trvium is certainly no exception. I'll be out in the parking lot working on my concert buzz right up to about 8:50 the next three nights. There's no reason to hassle with trying to smoke indoors when the parking lot is perfectly accommodating (and in some places, the cops care less than the hired goons).