Vitalik says: "if you like proof of work", after the merge, you should mine ETC". He's just a comedian. Ethereum classic is an empty shell, and he dares to say such bullshit. There are plenty of interesting and much better coins to mine than this Ethereum classic crap. Basically Vitalik is telling us to run mining rigs with no real use except for financial profitability (because ETC is only profitable). Amazing. Personally I prefer Ergo which is a real project with real developers and an excellent vision, or Ravencoin, Flux, Firo, Beam or Zano.