The reason abusive textbook practices persists (i.e. instead of free/shared) is because students and parents direct their anger and complaints in the wrong direction.

Specifically, the people making you waste money with bi-yearly re-releases, one-time-codes, or $150 textbooks, isn't actually the publishing houses. It is the gatekeepers at your very school: professors, department heads, and or the administration. Publishers are acting in an immoral way, but publishers by themselves have no power to force you into this abusive relationship. Your school is the one enforcing this, and yet few students file complaints at their school about the situation, protest, or otherwise make it an issue at THAT level. The level where they actually have leverage, and their complaints are more likely to be taken seriously.

Instead accepting the financial relationship forced upon them, and complaining that they wish publishing houses were less abusive. Publishers actually have little to no power themselves to force you into giving them money, your school does. So start complaining loudly and often at the school level if you want to see change. Every single year, every single class.