Standard APIs for many high-level languages are supported across Windows/Mac OS/Linux.
And the APIs that are OS-specific are a very small area of the code.
Games were mostly released for Windows, because Windows had an overwhelming market share (over 95%).
With Mac OS's share increasing, you see more and more games being released for Windows/Mac and also Linux.
I know about the massive market share Microsoft has in the OS market, that's not the point. We're talking about companies making it's own exclusivities. Now, have you ever seen a Microsoft game that runs natively on Mac or Linux? Do you realistically expect Microsoft to launch PC games on other OSes? Well, i don't. It may not look relevant now because Microsoft doesn't give a fuck about PC gaming anymore, but it's the same exclusivity that happens in the console market.
Fun fact: Halo was supposed to be a Mac game. Guess what happened to the Mac version when Microsoft bought Bungie?
Companies sell generic computers (PCs, Macs) at a profit and people buy them.
That's not a fair comparison. PCs are overall much more expensive than consoles and they're targeted at completely different markets.
Consoles can't be sold at a profit, because what they offer is inferior: a machine that only does a subset of what other machines (PCs, Macs, even tablets) can do and whose main selling point are the exclusive games they acquired.
Consoles are meant to play games and they're not inferior to a PC in any way at this specific function. Don't mix things up. In fact, you'd spend much more buying a PC able to run modern games than a console. For those that want to play their games without the hassles that surround PC gaming a console is a far better choice.
According to leaked specs (some have been confirmed by Sony) the PS4 will have a 8 core AMD CPU, a HD7970M and 8GB DDR5 memory (!!!). Being realistic the PS4 will cost U$500 at worst. There is no way you can buy such a powerful hardware to play games at this price, and i'm not even taking into account the fact that consoles are far more efficient than PCs at running games, since they don't have Windows as a middleware.
The core of what they are selling is still crap.
Crap like the hardware specs above?
Exactly. People go "why would I buy that crap when I could buy an actual computer for a comparable price?".
You do realize that there are many people who want an easy "put the disc in and play" experience instead of buying a gaming PC? We are on a PC gaming forum, of course everyone here is experienced at running PC games. But we are not the majority.