Actually yes, they can be considered major. Marxism-Leninism (broadly defined) and Trotskyism are the two most influential communist ideologies. Besides the former having the USSR, China, Cuba and other states (and the various parties loyal to them), the latter had/has plenty of notable parties (LSSP in Sri Lanka, the Algerian Workers' Party, the Militant tendency in Britain, etc.)
What you define as "worthwhile" has nothing to do with them being major or not. To the present day they have been incomparably more influential than Left-Communism.
Until the day when the average person immediately thinks of Luxemburg or Paul Mattick upon hearing the word "Communism" (rather than Lenin or Stalin), this will remain the case.
* h0m0revolutionary: "neo-liberalism can deliver healthy children, it can educate them, it can feed them, it can clothe them and leave them fully contented."
* rooster: "Supporting [anti-imperialism] is reactionary. How is any nation supposed to stand up [to] the might of the US anyway?"
* nizan: "Fuck your education is empowerment bullshit, education is alienation, nothing more. You indulge in a dying prestige for a role in a bureaucratic spectacle deserving of nothing beyond contempt."
* Alexios: "To the Board Administration: Ismail [...] needs to be eliminated from this forum."