I would say those are two HIGHLY subjective questions!! ;D Personally I don't think it's desirable if it is to the exclusion of others (as became the case after 1917). But I don't think it's a contradiction in terms - they clearly have existed.
Are you yourself Greek, (given your user name!)? Had you heard of Femelidi before? He is totally new on me.
His second name was Oleksandrovych - thus Volodymyr Oleksandrovych Femelidi, born in Odessa in 1905.
He was very much committed to the construction of a new proletarian culture and was enthusiastic about the achievements of the Revolution, which he proceeded to extol in a number of works, such as the opera Razlom ("The Break") and the "Jubilee" Symphony.
But is a "proletarian culture" desirable? It seems almost a contradiction in terms does it not.