You guys really going to give up online play just for homebrew/piracy? I mean I guess if single player games are your jam then I can see the point.
Actually, yes.
One: I've never really been into playing multiplayer with people I don't know. Given the choice, I'd rather play with somebody who I know and who I can knowingly and easily play multiple games against. I like the "talking to" aspect of multiplayer, but you don't really have that same friendly aspect with online multiplayer.
Two: I'm a big fan of RPGs and platformers. As a result, a huge majority of my games are single-player games. Out of the games that my family owns for PS4 (although the system is personally mine, my family will buy games for themselves) my collection is: "World of Final Fantasy", "Final Fantasy XV", the two "Kingdom Hearts" compilation discs, and "Persona 5". The family's games are two "Just Dance" games, "Zombie Vikings", and a "Call of Duty" game. The only one with a major online aspect is Call of Duty, and my little brother has an issue as it is when he plays that game without multiplayer.
Three: I live in a college dorm and visit my family on weekends. As far as games go, my options are either to haul my desktop back and forth, or take my PS4. The PS4 is much lighter and easier to carry, and powerful enough that when I can get emulators working on it (I got mine on 4.5*something*, I think. I need to double-check), it will play all of my favorites in a single lightweight box. College is expensive, and I'd rather use something I already own as a potential emulation box. Also, my siblings are young enough that a majority of games that I grew up with are things that they've never seen before, and they're not the kind of people who think that only graphics equals quality. I know a number of old Super NES games that my little brother likes, for instance.
Finally, and this is probably one of the low-priority reasons, but I lost the power cord for my PS2 when packing up for moving, and the PS4 has a working PS2 emulator in it, if it's set up for homebrew. Considering how many games today are remasters/remakes/rereleases of PS2 games (Jak & Daxter, Ratchet & Clank, Sly Cooper, .Hack//GU, Kingdom Hearts, etc.), it would be nice to get my collection together in a working condition again. (Although when it comes to graphical quality, I'm pretty sure I'd be better off with PCSX2 on my desktop. Bit of texture sharpening + saturation adjustment as well as increasing the internal resolution, and I swear that emulating an English-patched "Final Fantasy XII - IZJS" looks better than the remade version, runs perfectly other than some slight slowdown on the Limit Break-style attacks, and was available MUCH sooner than the remade version.)