Honestly, I think Cats does have artistic merit, but it is primarily in its designs, staging, choreography and innovation. I always hear about artistic merit being attached solely to the book and lyrics, but Cats was never intended to be a conventional book musical, so they heightened other artistic elements of the show knowing they were using Eliot's poems as a springboard for a highly stylized piece. I always see people attempt to fault it for this, but I don't get why. Ad as for the music, I think Webber wrote several stunning tunes, many of which were quite catchy, melodic and memorable.
And I get what Gaveston is saying about Broadway riding the West End wave, but that wave had to start somewhere. Other West End successes have not fared well on Broadway and vice versa. Cats was already a smash in London before it transferred. The positive buzz came from the audiences and critics that had seen it during the pre-internet era. It gained a reputation and it was something completely new and different. It's not like people were flooding the box office hoping to buy a ticket to something they heard was just sort of okay. They were intrigued, they wanted to see what the fuss was about, and they told two friends, and they told two friends, and so on...and so on...and so on.
Thus was not the case with Canterbury Tales, Buddy, Joseph or Aspects of Love.
"What can you expect from a bunch of seitan worshippers?" - Reginald Tresilian