Yes... I've heard it a million times. By the letter of the law, they were within their rights... but President Trump is not a typical user:
Mr. Trump was, at the time, the standing President of the United States, Leader of the Nation, and Commander-in-Chief of the US Military. These social media corps are located in the US, and enjoy the privilges and protections of its government.
For Twit FB and Goog to strong-arm and censor T is truly a slap in the face. Not just to him, but to the Office of the President and freedom of speech itself.
Perhaps most important is the ultimate censorship of his voters, roughly half of the US. Trump's censorship amounted to a censorship millions of his voters. Adding insult to injury, a large chunk of his presidency is lost: all his Twitter posts, etc.
I'm sure you're thrilled about this, but there is a simmering fury present here. Donyou at least see my point of view? What if Obama were to be gagged/canceled like this? You'd be screaming bloody murder.
When people are censored in one way, their voice will be heard in another.
This is far from over.