I don't know if they have always been as expensive as they are now, I'll admit I'm not a fashion writer or anything, but they have always been more expensive than something like Carhartt as long as I've been around.

Historically, the quality justified the additional cost for hard work, even when Carhartt was in its better quality years, and especially if you wanted to not be throwing stuff away often.

Currently, from what I've seen and read, they have turned wholly into a fashion brand. Some of that is good, more modern cuts, some cool t shirt designs, and makes it more likely to continue on. However, it's also bad for durability, since as the market is more fashion focused, people demand clothing that is soft and fits well for casual use.