This isn't accurate. It might not threaten your life or pose any great hurdle to overcome but retaliation has nothing to do with that. If they did it in response to an action you took not to solve a problem but instead out of spite or to otherwise get back at you then it is retaliation.
That isn't the same as refusing to do business with someone who isn't productive to associate with. The two are entirely separate categories.
Of course any business (including Steam) will attempt to argue that an instance of the former is actually the latter, and a difficult customer will attempt to argue that an instance of the latter is actually the former. Regardless, Steam (and most other businesses) behave in a clearly retaliatory manner regarding chargebacks. In cases where the company failing to respect the individual's legal rights is what led to the chargeback that shouldn't be permissible.
To frame it in the terms you used, any otherwise legal activity stemming directly from the company having violated an individual's legal rights should be treated in the same way that a protected class is.