Mozart wrote good music , when he wrote it was not his SOLE intention to make money, that in my opinion is the difference.
MacColl, [in my opinion] stands out as a songwriter because he cared about social injustice, he could not have written as he did , if his SOLE intention was being commercial, the song that he wrote that became a number one hit was written with passion for his partner it was not written with the intention of being commercial , its success was an accident