Getting into repeating myself alittle, but hopefully this clears it up a little
Take TLOU Factions Multiplayer for example. Usually something badass will happen in one of our matches on the PS3. Unless a person has a capture card that moment is lost forever. The PS4 Share Button is a genuine improvement, and would allow those moments to be saved/shared forever. These friends always bitch that their teammate didn't see their epic moment, so I tell them to grab a PS4 and use the share button. They balk at the PS4 price, but still plan to get this years, or next years COD, AssCreed, FIFA, Battlefeild or whatever else. They are actively harming their own play experiences because there exists a cheap and nasty solution of continue buying the last gen versions. However if this and next year's blockbuster games were only current gen, then suddenly their experience would be improved. This isn't just TLOU either, it would be the same if they pulled off something cool in the upcoming cross-gen FarCry4 too.
Meanwhile, whilst they're doing that to themselves, there's now a divide in our group. Those of us that are current gen, and those that aren't. Those of us that aren't are going to save money but have a bad experience. Those of us that are, are looking at either buying a lesser version of the game in order to keep the group together, or god forbid buying two versions of the same game. That a last gen version exists is really a pain. Without the last gen version those friends whom are back there would quickly find a nice stock pile of games they want to continue playing the next iteration of, and would find the justification for buying the new system. And all the other benefits which come along with playing on the new system.