You confuse the point as it relates to businesses consuming Free Software and developers employed by said companies.
If your business depends on Free Software, then as a business it is in your best interest to help shape it. If you work for one of these companies and they prevent you from participating then quitting is a sensible option - for you and for the company. Eventually brain drain will force these companies to reevaluate their position and take a more active role, till then good fortune has it that the sector is booming, jobs are not far between so quitting is not neccesarily a bad choice. That is if you, the developer, enjoy being part of the Free Software community and participating actively, if not then by all means enjoy your job.
Not once has the Canonical developers been blamed for Canonical' lack of contributions, that is a business decision, as such the business is the one with which the problem is debated.