With the new kernel version increase, and the less than acceptable justification, ofcourse there tends to be speculation. Some are suggesting the kernel is prep'd for systemd integration, others claim its a precursor to something ominous. But just like the increase from 2.x to 3.x, there will always be the naysayers. For me I just find it odd, not only in the timing, but the atmosphere. I'll be looking for alternatives now. The one I'm building out now is OpenIndiana, the free version of opensolaris OS/Net-based derivative kernel known as Illumos.

Because they bumped up the version number from 3 to 4?

My thoughts also.
It's a version increment for frivolous reasons because Linus is Linus and can do it.
Or, the Crab People are being paid by the Reverse Vampires to version number it up so that they can steal the souls of every Linux user by using the number 4 which is like the number 13 minus 9 which can be used in nine's-complement arithmetic which is like two's-compliment which is what is used on common processors?