Even if a communist can colloquially describe themselves as being on the left, there’s a distinction between communism and “the left.” This is implied right in the title of Lenin’s Left-Wing Communism: an Infantile Disorder. Whereas the left, a big tent term for a myriad of incompatible ideologies, aims merely to act as an opposition towards the present order for the sake of it, communists have a coherent vision for how to defeat the system: by advancing history’s development to the next stage. The left, because of its lack of commitment to that central Marxist goal, naturally takes on an opportunistic role. Because when you want only to build a movement as an end in itself, rather than use this movement as a means for defeating the system, you become nothing more than an actor who benefits from discontent without helping solve the problems behind that discontent.
While I respect your willingness to call a spade a spade as you see something as such, I have to disagree with much of what you have said. I’m unfamiliar with Sakai, however comrade Shea does not come off as a settler-minded person to me. I will also note that although there are far less minorities in the bourgeois class, there still are some, and so a race-based analysis will not suffice here as a shortcut towards class, nor should it even if this were the case as liberalism is the ideology which views the world according to conqueror v conquered constantly seeking exploitation of another, as Marxists we view the world through dialectical materialist and historical development - the clashing of opposites based on their contradictions to create a new tomorrow, not the outright rejection of a portion of that synthesis.