Re: I wonder why
If you go after the top level, they will (theoretically) be motivated to close vulnerabilities down.
By going after lower hanging fruit, your choice of targets will never dry up.
Personally I think the size of the attack surface and insecure-by-design OS features favoured (mandated?) by the NSA and MI6 is a major contributor. It is time to draw a line under and stop using them. Anything worth protecting deserves a proper OS with minimal attack surface - with the possibility to subject it to thorough testing. As opposed to the common-as-muck bloatware that is impossible to test every angle.
Some moves in the software space to develop "safer-by-design" languages and compilers are welcome.
Offloading data to clouds is trendy, in much the same way that Mainframe used to be the accepted computing paradigm. The inconveniences of mainframe apply to clouds also; and in fact are worse because you don't even control the hardware.