Alot of casual fans won't see them every tour.
I had a columbian friend over for super yesterday and he said he saw them 5-6 years ago in Montreal. I assumed this was the circle GH tour. He said it was a once in a lifetime kind of thing. It was good, but he wouldn't see them again. (he also mentioned that growing up, he kind of had BJ forced on him by his girlfriends, so knowing some songs always helped him with the ladies).

My ex-rommate also went to see them on that tour in Montreal, even if he wasn't a fan. I think they played 5 or 6 times in 18 months there for this tour, so they probably had alot of casuals show up throughout these shows, as is probably the case for all their tours.

I think it's only normal that attendance is down a bit, considering who else is touring and how often they've toured recently.
Unless they are releasing material that helps them gain NEW fans, I don't see how they are going to turn the trend around, especially if you look at how these shows are going.

I'll still have fun at mine coming up, but I don't see the band impressing casuals to a point that they'll come back or convince others to join them next time.

That used to be the case though.