I happen to agree with your first para, but I think indifference and dislike are separate
I am indifferent to warhols work because I already agree with the inherent message and find little beyond that message
You can even dislike Warhol for other reasons, but it still remains that disliking the work for its mass production qualities means you are responding as intended
As for your second para.. you seem to be an adherent of a dull and unskillful ideology
I think all art takes skill, of varying types of skill, but more specifically a lot of modern art(o) consists of paintings that inarguably required a lot of skill to paint
You seem to be arguing something other than modern art
Personally I think it's dangerous to apply limitations on how others can express thaemself