>All this money should have been spent on developing new, improving existing or switching to better (operating) systems which solve the resource and communication security problems

But this isn’t the problem Docker is trying to solve. It’s just a problem that Docker needed to solve in order for their product to be useful, this is completely transparent to Docker users. Docker abstracts away a whole bunch of work you’d otherwise have to do to implement repeatable builds, it makes those builds widely distributable, and (depending on how you choose to use containers) can also simplify some capacity planning problems.