There's a very good reason for the sentiment and why people feel such a sense of dejection and apathy. Then it gets met with smug ripostes like the "bOtH sIdEs" spongetext shit or plain mockery as if it's something that just appeared out of nowhere.
It's just typical Democrat arrogance assuming that they are entitled to peoples votes without having to offer any material change, it also ties into why progressive and leftist candidates have to struggle to break through because they're fighting their own party first and foremost before they even get to fighting Republicans.