Main frame creates lockin
Sure there is an argument to say it is cheaper to maintain as it is all one, but it doesn't really fly in the real world. It is better to build a varied interoperable network of computers that you can turn into a huge cluster if needed, that's a far better solution.
It is all going to smaller and many, not larger and one, it is more cost effective for more scenarios.
California may not have moved off mainframes, but that is not a testament to mainframes that's a lock in, and it will cost them more in the long run. Though the longer they can hold off, the cheaper it will be to replace, so at some time the sweet point will be found and off they will go to micro and distributed world, joining the rest of the human race.
