That's not really true. The right created Gab, and Ruqqus, and Voat. And they managed to hijack the U.S. legal system which the left can barely understand, let alone influence in any appreciable way.
A good chunk of the left (not the Dems, the actual left) understands the US legal system. It’s just that it’s hard to win in a pay-to-play system when everyone who can pay is against you.