Earlier quoted context omitted.
You can't take the costs provided by journals as a minimum because they are likely providing services that are no longer necessary or could be made much more efficient. Here's an example of how to do it on the cheap: "Scholastica charges us $10 per submission. We have a grant to cover this and our other costs, which are very low. Our total costs probably average about $30 per accepted article. Therefore, there are no…
If authors find that such journals fulfil their needs, then the traditional publishers will have been outcompeted. But make that case directly; don't yell at traditional publishers for being expensive, when they also provide far more service. If you don't think it's needed, don't use it.
That's the problem with the current system, though. The authors aren't choosing a journal for the extra services the publishers provide, they're choosing it for the prestige associated with e.g. Nature. It's similar to the reason why any new social network, no matter what features it has, would have a hard time competing with Facebook.