These corporations are societally expected to uphold a cultural respect for free speech and the rights granted in the First Amendment, but there is no legal basis to compel them to allow speech or activity they do not approve of.
Extrajudicial behavior such as terrorizing a legislature is harmful to these corporations’ profitable predictability. Operators would be in violation of their fiduciary duties to allow such a direct threat to their bottom line to continue, let alone grow.
In other words, money cares more about itself than anyone’s feelings.