I would attribute the "unfashionable association with suburbia" for Rolex to the very very high visibility of Rolex ad copy, as opposed to some inherent tackiness with the brand.
The "lifestyle of McMansions, large SUVs, shopping malls, office parks, etc" is IMO to a significant degree one of conspicuous consumption and social signalling, and it would logically follow that a popular, high visibility prestige brand like Rolex does well with that segment of the population, not unlike BMW. Sort of like the lazy way out for someone who wants something "better" but doesn't want to do tons of research prior.
Yes there are people that buy a Rolex in an effort to show off. However, there is also a huge segment of Rolex buyers that are not WISs. They walk into a dealer with the idea of treating themselves to one good watch to last the rest of their life (they may even buy a his & her set). They have heard of Rolex, the dealer tells them its a good, sturdy, reliable watch. its versatile, and will last them the rest of their lives. They walk out with a DJ in steel or steel and gold, or if they splurge they buy a Day-Date. They want one watch to wear forever, they were never going to buy something exotic and delicate such as an FP Journe or a Calatrava, as those are not going to fit their lifestyle...those are for a WIS. In addition, the pricing on a steel and gold model is far below something from PP, AP, Lange, etc...so those were never going to be considered. You get some overlap in pricing on an all gold Rolex and some "Moderate to less expensive" Pateks, APs, VCs, but realistically as much as I love those brands...if I could only have one watch to last the rest of my life for every activity, I would easily go with some form of Rolex...the others are just more delicate and I don't think would hold up as well in say 30 years of daily use.