I honestly don't understand why people refuse to buy consoles without backwards compatibilty. Is that hard to just keep your old console? Even if you don't own a last gen system they're very cheap now. Adding BC would do nothing but drive up the costs of the machine and make it an architectural nightmare. 

If PS4 and Xbox One had backwards compatibility, maybe the systems wouldn't be nothing but later released last gen ports.

It's convenient.

Convenience. My TV only has a certain amount of ports, and as a college student I can't take all my consoles with me to the dorm.

BC isn't a deal-breaker, but it certainly is something nice to have.

because is better

Cause we have a gf/wife who doesn't like it how multiple consoles clutters up the TV space..

*high five for all who have been there*

I can get the convenience aspect. Having one machine playing everything instead of one for each generation does seem practical. But people do exaggerate on it. I've seen someone stating they would only consider a PS4 if it ran PS1, PS2 and PS3 games, so he could catch up with previous generation. Why not buy a PS2 in this case...? Anyway.

And considering the bizarre architecture of the PS3, anyone expecting its games on the PS4 was delusional. And Sony's situation probably doesn't allow them to include PS2 parts on every single PS4. Maybe software emulation is possible though, who knows.

My issue is that I like to keep one or two systems to play games on and when a new generation starts, I would like to get rid of my old systems and make room for the new one! But the issue with consoles that don't have backwards compatibility is that:

a) They don't have enough games to keep me entertained until at least the second year b) The old systems still have games coming out that I want c) I sometimes want to go back and play the older games which = bringing back my old system from its dustbin

With that being said, I don't buy a system only cause its not backwards compatible, I don't buy it for other reasons + a lack of BC

Oh and the other issue is that when the system is not backwards compatible, that usually means that we have the rebuy the games we already own in the future if we want it to play on the current gen console which is terrible imo. I am not saying we should be able to play games from 2 generations back but its always nice to play games from the last generation without having to rebuy them in VC

Because one console has it while the others don't.

In reality backwards compatibilty is probably a feature that is barely used anyway, which is why it's not even a real selling point anymore even if you have it.

If you still have a large 7th gen backlog you now have to either keep two or three or more consoles hooked up if you can, or switch them any time you want to go between them. Selling your old system can also be a great way to lessen the financial blow of an expensive new piece of hardware.

Also if you didn't own the company's last gen system backwards compatibility essentially lets the console launch with an already expansive library of non-$60 titles for you to try in the seemingly inevitable dry spells of quality titles in the first most of the first year of a console's life.

AND being a college student I can't take all these systems with me. That would be expensive and it would probably also take way too much space. I use BC quite often on my WiiU and 3DS, and if the ability to play games designed for like Windows 98 on my PC counts as backwards compatibility, then I also use it there.

And maybe BC would make it so there are fewer last gen ports. -_-
BC's not necessary, particularly after a year or two to most people, but it sure as hell is convenient and a nice bonus. A system that has it would be more appealing for it, compared to one that lacks.