It's neither, it's just life. Millions of people just in the US alone splurge on things like luxury cars, huge mansion houses, expensive country club memberships, suite tickets for the local sports teams. The only problem with a hobby (like PC gaming) getting popular is now you got people in the top 5% income bracket interested and they aren't interested in bang for your buck or value for the dollar they just want performance.
Exactly. It's not like people are pulling risky high interest loans to buy these cards, it's just people that have lots of disposable money are now interested because the hobby is becoming more popular. Every hobby I've ever done in the last 15 years has gone through phases of this (PC gaming, trading cards, retro cars, vintage guitars, golf).