I think there are many factors. First, learning music/guitar takes effort. Decades of video game mentality, couch potatoes who haven't gotten off momma's teet, and kids counting on momma to even change a toilet paper roll, laundry service and to be their money tree, don't lead to a generation that puts in the work needed to play guitar.
2nd, today's economic environment does factor into where money gets allocated. Houses, health care, cars, etc all are expensive.
The higher priced guitars are a luxury, and luxury money is often not there with the ever increasing demands on our wallets.
More reasons, just those 2 come immediately to mind.