It is not so much a matter of the dead and the living, it is a matter of the living and the dead. In the beginning it was an article of faith that all painters were basically the good men, and the good they did was the reason the dead were not the great artists that they were. As time went by and as painters became better, those who held to the older beliefs began to speak against them. They claimed that the painters brought on their misery by attempting to copy the previous great painters.
As time wore on, these painters became more respected, especially in cities that hosted large art exhibits. They were thought to be trying to copy the works of Picasso or Monet. In this case the two painters in question were considered to be better painters than the originality of watercolor. Thus, the debates were fought over; those claiming that the watercolor painter copied the work of the master. Others argued that the watercolor was an inferior form of painting.
The debate over who is the real artist has raged on for years. There have been articles written about it as far back as when the concept of the Abstract Art movement started. One of the main articles talked about how Monet painted his paintings from memory, and not from a photograph. And as you might expect, there are still arguments about who is the real artist; Monet, the photographic painters, or the other man with a paint brush.