CDPR made a large portion of the game when they only had a basic idea of what the next gen consoles (PS4, Xbone) were capable of in terms of graphic fidelity and hardware; this is around the time they released the SoD trailer. Afterwards, they got their hands on the next gen consoles and realized that it was not possible to play that version of the game with the PS4 and Xbone- so they had two options: finish the PC version, or start from [essentially] scratch, and rebuild a version of the game that would be playable on current gen console hardware. They elected to make the latter, as finishing the partially completed SoD PC version, and then going back and changing all the textures, engine, etc. for the consoles would take more time/ resources than they wanted to spend. This is why they did such a thing.
All of this is understandable, from a business standpoint, though people are displeased because they chose consoles over PC, and essentially 'sold out' because there is generally considered to be more money in consoles. I'm not entirely sure why Marcin and the other devs lied about it repeatedly, I presume because they didn't want people to cancel their preorders- mission succeeded I guess, the game sold more than 1.5million copies before it even launched.
The whole dishonesty thing really rubs me the wrong way; I used to think of CDPR as the good guys- a company that didn't use DRM and were gamers themselves, a company that didn't practice 'big business' and shitty business practices for maximum monetary gain, regardless of the impact on the final product and existing fan-base. Oh well, money gets to everyone I suppose.