The first fact you need to deal with is that open access journals, started to explicitly counter the cost problem, have similar costs. If it was as simple as you think it is, open access journals would be much cheaper. (Arxiv is not peer reviewed, and does not count.)
The second point is that publishers costs are around 70% of revenue, as the article says margins are around 30%. That means there's a limit to how low they can go and not lose money, and I doubt many of those complaining would suddenly stop if prices were 30% lower.
The second point is that publishers costs are around 70% of revenue, as the article says margins are around 30%. That means there's a limit to how low they can go and not lose money, and I doubt many of those complaining would suddenly stop if prices were 30% lower.