You attitude, while essentially correct, is that of a top F1 mechanic dissing SCCA amateur racers for building their own cars. Very little of what they do "matters" in a commercial sense, and nobody gets killed in a five song pileup caused by someone's home studio mastering errors. Meanwhile they are making all the mistakes that lead to a deeper understanding of the process. Though few will ever be real mastering engineers some will come to have an increased respect for the profession. They are your future clients. Chill and let the people have their fun.