[DarkKomunalec]

The US has already decided that the right to sue is fundamental: http://www.firstamendmentcenter.org/right-to-sue/

Such waivers limit this right. I struggle to imagine an ideology that thinks giving up a fundamental right is wrong, but limiting it is ok. Given how rarely arbitration courts rule against the one who selected them, the difference between limiting and forfeiting the right entirely is slim to none.

[Chaebixi]

I think the way they justify it is that the waiver is "voluntary," e.g. you have to agree to it in a contract.

I personally wouldn't have a problem with that if the contract terms were negotiated by two sophisticated parties. However, the reality is that these contracts are often pro-forma and and "signed" without negotiation in the context of great disparities in power and sophistication. IMHO, the latter is troubling and shouldn't be allowed. There should be a whitelist of a limited number of types of terms that can be included in a pro-forma contract like these, and binding arbitration shouldn't be one of them.