The problem is not with sony, they now what their doing. The problem is with customers because they are not educated enough in terms of new technologies. Customers knowledge is way behind the hardware capabilities. Ill give you an example.
Most of customers cry about lack of backward compatibility and mp3 and cd. But the fact is no one would ever used those features in PS4. Rather listening mp3 on PS4 you would use your mobile phone or iphone or mp3 player because it's more convenient and more comfortable. No one would ever play PS3 games anymore since almost every one want's to jump on PS4 and Xbox One. So why you would bother ??
Customers are not educated enough these days. Backing up your theory with saying that PS3 would take some space under your TV is the proof of that. Your TV has multiple inputs, there is at least 3 or 4 HDMI inputs you could use to connect new device such as PS4 or you could also use component cable. PS4 comes with HDMI cable, so sony think that through. Most PS3 users never used more than one HDMI output if they had only one console. Thanks to PS4 this would change. Or if someone still decide to sell he's ps3 to backup cash reserve and buy PS4 then it's just like i tell you. He's not educated enough in terms on new technologies. Being unaware of what your ps3 is capable and selling it to replace with hardware that doesn't have those capabilities is the customers fault. Sony did good thing by cutting cd + mp3 + ps3 backward compatibility, and media server. Since you already have device i mean PS3 that can do all that there is no reason for PS4 to have them.
You already have media server in your PS3, why would you need it in another device ???

Keep your PS3, problem solved. 💡