Trail Ready has been around for quite a while I believe. Several years ago, 15s were very popular. Now the 17 is the new 15. With the addition of the bigger brakes etc, the 17s are more popular. I also think its due to peoples general like for bigger rims. 10-15 years ago in the aftermarket world 20s were all the rage (mostly on road vehicles) now a lot of vehicles come from the factory with 20s and people want 22s or 24s etc. So I think naturally the want/popularity for the bigger beadlocks took off as well.
Just from reading on here, not all 15s fit and most i believe will not allow you to run a drag link flip kit. So I would do more research into that before purchasing rims. Also the obvious of no longer being able to install a big brake kit goes away. There are also still a lot of tires in a 15 inch rim but they are becoming less common and you basically have to order them. Usually you can find 17s in stock at a lot of places, even in a 33 or a 35 inch tall. Not always though.
Just my two cents and something to think about.
