The whole point behind POSIX was so people didn't need to constantly reinvent the wheel and glue things together to do simple things on different platforms. Today if you need to do anything in the cloud, you must "integrate" the pieces, which means to take out scissors and glue and toothpicks and a text editor and literally arts-and-crafts the pieces together. Want to add something to your system? More arts and crafts! Rather than waste all that time, if everything just used a common interface, everything would just work together, the way it (mostly) does with POSIX.
This is bad for the companies that make all their money off proprietary/incompatible interfaces - lock-in devices that are advertised as a plus because they can be "integrated" with enough time and money. But it's better for our productivity and the advancement of technology if we didn't have to integrate at all. Just run the same thing everywhere.