Of course it's about making more money, and in some cases it may even be because the game didn't sell enough in the console and they're doing the PC port just to get back all the invested money (Days Gone would almost fill this criteria), but Sony knows that their console will be sold at a profit sooner or later, and the more they sell, the more profits they'll get from it. Just like PS4, which was due to some price cuts a long time ago, but they didn't because it still sold well and that mean more money for them.
Because of that, Sony won't risk that side of their business, and their position as a media center for the living room, by launching their latest games on PC alongside the console version.
Besides, some of their games sell well for longer periods of time, like Gran Turismo, so launching them earlier in the gen is not as big of a problem as it could seem.
By the way, those 17 unknown entries in Steam aren't all games, they are games and DLCs. For all we know, it could be 17 games or 5 games and 12 DLCs for those games.
Please excuse my bad English.
Currently gaming on a PC with an i5-4670k@stock (for now), 16Gb RAM 1600 MHz and a GTX 1070
Steam / Live / NNID : jonxiquet Add me if you want, but I'm a single player gamer.
