Why? A 50gb install per game? In fact I recall sony saying 0 loading times ever for games... yet not only did nba 2k13 install itself onto the HDD..... but it has almost the same lengthy loading times that 2k13 did on the ps3..... and the game although looks much better... doesn't look so good that it has to run on both the disc and the HDD for it to sustain 60fps at 1080p on a console 10 times more powerful than ps3 with 8gb of ram....

why is sony forcing 25GB + installs for games???? When games like KZ2, which looks arguebly as good as nba 2k13... with way more going on, runs with mb on the HDD... on the ps3, and even less loading?

Noise, ODDs are set to break over time, loading times... Also keep in mind games don't use all 8 GB.

ODD what?

Regardless of how much Ram you have, how fast a Hard Drive is, if an Optical Disc drive isn't fast enough to stream data as it's needed, you're going to need to install the games and have load times.

Only way around it is if drive manufacturers started increasing the RPM's to a few thousand revolutions or do what Kenwood did and instead of having a single optical laser, used 7.
Of course, that drives up costs and noise and stuff, not something you want in a cheap device.

Optical disc drives.

But counter to that is ODDs seem to last quite a long time, and HDDs also break.

PC's pretty much always install games more or less completely, so PS4, and I assume Xb one, are just following in PC footsteps.

Remember: You bought a Sony PC.

It's too keep disc games and digital games with identical parity.

This gen the relatively small installs you were used to were accessed in tandem with data being streamed off the disc. It allowed devs to get better graphics out of the console. However this trick obviously doesn't work with digital games since they don't have a disc to stream from. It resulted in digital versions of GTAV and other games having worse texture pop in.

To make digital games not have this problem, partial installs are now gone. Instead the game either streams just from disc or dumps all the data to your hard drive and streams from there.

You don't really "install" games on the PC anymore.
Games you buy on Steam, Origin, uPlay, GoG etc' are downloaded and run as-is with the exception of a mandatory install of Visual Basic Runtime and Direct X to make sure everything will work fine.

That's where the bulk of PC games sales are anyway, which would be the more relevent comparison point, if you buy a game on one of those shiny drink coasters, then you have a choice to download with the product key or install.

Why are you so bothered it installs as you play, so even with larger installs youll be in and playing in under a minute in most cases, rather than the 20+ minutes of the smaller installs of last gen. 

The size increase is mostly due to more detailed textures, to fill up that that ram and 1080p framebuffer, it really is a none issue, if youve got crap internet buy box product. 

Look, Ram got 16 times bigger ( 10-14 times for the crucial vram), while the BR drive is only 3x faster than the one in the PS3 and even back then not everything could be streamed from the disc into ram.

Just by this you should see that if you want those bigger textures to load into ram quickly enough you need to install them to HDD.