What is the deal with all these big 19 and 20 inch wheels on roadsters and coupes?

[Perfectlap]

Time for a rant. I'm shopping a second set of wheels. Actually more like fourth but that's another story. I currently run the factory 18" Carrera lights with the excellent RE-11 for summer use. For me this is really pushing the tire size. Ride quality and performance don't seem to improve with less rubber.
Aesthetically I'd rather see more tire hugging the wheel arch and not this big wheel on rubber band tires. Why is this popular? Small cars look ridiculous with so much visibility into the wheel arch area. Virtually all of the traditional Porsche wheel (aftermarket) manufacturers offer only 19" and larger. In the rare instance that I see 18" or smaller in the aftermarket they tend to be extremely over-priced for cast alloy. Some like CCWheel make an 18" wheel but there's not many choices and there's no such thing as a moderately priced forged wheel which are usually intended for racing. Not to mention a new set of those puppies correlates to 30% of the value of any given second hand Boxster and those 996 Carreras aren't holding value much better.
This just doesn't make sense to me. Has the sports car market just been taken over by people who demand big wheels and fewer tire (more expensive) tire choices? I don't get it.