Don't get me wrong, I'm primarily a PC gamer, so I'm fine with the idea of dropping cash on my gaming machine every other year for an upgrade. Problem is, one of the most appealing parts of a console is not having to do that, and perhaps more importantly, knowing you can wait 2-3 years for a lower entry point from a "slim" redesign before upgrading to the next generation. You're right that technology gets more affordable over time, but console gamers are used to that saving being passed on to them, not seeing a console permanently sitting at the $300-400 mark and improving graphically every other year.
Regarding the 4k news - it's definitely feasible for PS4 games to output at this resolution, but I imagine that's mainly targeting smaller games (like Assassin's Creed Chronicles) and Indies that want to make use of it. AAA games like the Division and the Witcher 3 might be able to get a bump to 1440p, but I doubt Sony would be looking to fit a GPU that would be considered bleeding edge by PC gaming standards, and selling it in a $400 box, so that Destiny 2 will hit 4k. Seems to me the 4k is more of an "upper limit" thing that only a minority of games will take advantage of.