Commercial publishers, as a class, are not evil. To think so is wrong. They have just been doing what the scientific community can't or won't do by itself. And like most businesses, they charge what they can get away with. It’s known as ‘the market’. They can’t be criticised for existing and functioning in a perfectly legal capitalist market and regulatory environment. That doesn’t mean they can’t be criticised. Individual publishers can be criticised for their actions and inactions. As an industry, among the things they can be criticised for are not evolving fast enough, given the environmental change that the web has brought about. But so can the academic community. The reliance on old and now effectively dysfunctional systems and habits from a bygone era is mutual.
Centuries ago, in Europe, non-Christians were forbidden to belong to the guilds, which made it impossible for them to be any kind of craftsman, essentially leaving them with few other options than being an unskilled labourer, trader, or money lender. So some became very wealthy and thus became the target of envy. And accused of usury and the like. Just for doing the only thing they were allowed to do and society needed someone to do. It’s more complicated than that, but it captures the essence.
The relevance of this to science publishing? Well, at a certain point, when science had grown into a sizeable, professional and global pursuit, academics didn’t, or couldn’t, organise publishing properly anymore on that global scale. University presses were, by definition, rather local, and so were scientific societies. Commercial publishers stepped into the breach, some became very wealthy, and are now the target of envy. Or at least of criticism of their wealth. And accused of greed and the like. Just for doing some of the things the academic community needs or thinks it needs, in the environment of a ‘market’ (starting in the 1950’s with e.g. internationalisation of science communication; abolishing the sort of author charges the scientific societies were levying for their journals, standardisation of article structures, language, et cetera).
Lesson: if you leave it to outsiders to provide your essential services, because you can’t, or won’t, truly assimilate and embed those outsiders, and provide the services from within your own circles, you risk losing control and you cannot blame the outsiders for taking the opportunities you give them.
PS. The first Open Access publisher was a commercial publisher. The largest publisher of Open Access articles today is a commercial publisher. Why are there not more scientist-led initiatives like PLoS?