Yes, Scottsdale is a nice dry climate. Roaches cannot live there, just as it is in Denver.
I have never seen a roach in a Marriott unit. That is just true that Marriott does it better, but I also don't travel during the most humid/hot times of year. I have never seen a roach at Hono Koa, and our units are 35 feet to the water, but Maui isn't extremely hot and humid like SC is.
Our kids did see a few at SBP last month. I saw a few bugs in our unit for that same week, mostly by the door, but they weren't the big roaches. They were small, but I wasn't alarmed in the slightest bit, and our unit had no stains and no issues, except the bleach smell from the lockoff side. I did notice a space under the door where you could see sunlight coming into the unit, and that should be sealed with weather stripping, just to keep bigger pests out.
Sure, you can get a roach infestation in Denver, but you have to be a terrible housekeeper to get an infestation of roaches. I saw one in my laundry chute once that was dead, brought home from the firehouse when a guy decided to keep open food containers in his locker, which infested the entire old firehouse. That firehouse is long gone, Rick's old Station 9. They took it down to make a new ramp off of I-70.
Just to be clear, I think the roach problems at SBP are worse than usual, because Kellie and now Janie have both said they wish it would stop raining, so people would not be this upset over the bugs. If you are from Denver or another dry climate, this could really freak you out.