harsh, but information pays.
saw a Dell XPS tower at retail store for $900... had i7-6700 with cheap GT-730, and then an aisle down, Asus Oculus desktop, for $850, i5-6600 with GTX-970.
the idea here, is some people don't have the luxury of building extravagant systems, so sometimes pre-builds from good name brands are the way to go if the configuration is a good price/match up of quality parts.
we could all put that Asus Oculus computer together for cheaper, couldn't we? (rhetorical)
retail pricing, even if we got a deal on particular parts, it'll still be close to $1K, give or take, depending on upping the quality on something or dropping the price to take out that DVD-RW drive? some people want new, not used, is the idea here, too.
i5 6600 w/HSF - $230
motherboard - $50
OS - $120
PSU - $50
GTX 970 - $300
DVD-RW - $25
WLAN AC card - $30
Chassis - $50
1TB_HDD - $50
8GB RAM - $50
so far, it's 955, no shipping or tax included. doesn't even have an SSD.
lifespan, if the system is being pushed hard on a Delta 433w PSU, 6 months to 2 years, lucky if it can go five plus years on the best circumstances.
anyway, if the budget and circumstances call for AMD, it can work, usually combined with enough RAM, a good SSD and a decent graphics card and just enough easy-flow wattage from a cheap priced, but quality PSU. if stuff's on sale, go pre-built and modify the rig if need be, to save an extra $200 or $300, and labor time. not everyone wants to play at high frame rates, or even want to attempt the newest games at the highest frame/sec, at ultra settings, they want playable at 45 fps, if that's even playable for some...
at the end of the day, it's their budget and their circumstances. save the grace.
some people are okay with fluctuating 30/60 FPS on playstation and xbox consoles, displaying at 900p/1080p, and are willing to pay and play with that on high input-lag 4K TV's. so be it.