Moderation is highly subjective and Parler seemed to have limited moderation mostly to illegal speech. We have built an entire country on the premise of legal vs illegal speech and have very clear laws and systems in place for reporting and handling violations. If a company chooses to adhere to the law but not also impose their own biases when it comes to moderation, that is their right. As long as they are undoubtedly doing their best to actually adhere to the law and remove and report illegal content promptly. The technology exists to do this effectively. The real issue lies on the subjective preferences people have over what. otherwise legal, speech should be allowed to remain on the platforms. Clearly it’s a slippery slope which is the basis for the spirit of the 1st amendment in the first place. Whether the 1st amendment ought to apply to the subset of private companies which have collectively become our virtual public forum is a separate debate. But the concept of restrictions on speech still applies to social platforms.