There must be massive opportunities for entrepreneurs who can address parts of this problem.
Building secure software means that you have to think carefully at all levels about precisely what inputs may enter your software, and gracefully reject anything that you're not prepared to handle. The flip side is that you can't easily readjust your software when business needs change, because you've built your system to avoid unintended consequences and everything has to be specified out in careful detail.
The reason systems aren't secure isn't because they can't be - some very secure systems were built way back in the 60s (eg. Multics). It's because it's not economic for them to be. Insecurity is a conscious design decision, and for many markets, it's the right choice.