Here's how we got into this position. The Internet was designed to work within government laboratories in the U.S. of the size of about ten; it now connects 12 billion computers, and it's rapidly climbing, with essentially the same technology. Nothing has changed. It was never designed for security and security isn't really workable.
The bottom line is an economic one. You can buy a PC; you can put Windows on it for a couple of hundred dollars. If you wanted that to be a secure piece of software with a secure network, you'd be looking at $50,000, and that's why we live with the software quality that we do. It's a long history of economic choices, all of which at the time seemed reasonable, but which have got us to a place that's very hard to get out of.