So, do you think if these proprietary systems didn't exist, you would be able to do more interesting work, or not have a job at all, or just spend your time on writing scripts that convert file formats between version2.forka of database software x and version48.forkb of software x?

If you find your work mind-numbing, maybe you should have a look at yourself and find other work, rather than blaming others for the problems in your life. (ooh those evil software companies, they make me work a job where I get to sit on my ass in an office all day and still get paid double (/triple/ten times, depending on where you live) the median salary).