Well, if you're going to allow us Philistine imperfect conservatives to state opinions on art...
Why this example? I'm not sure this is such a common practise. I've never heard of it.
Nonetheless, are there no other differences a normal person might use to illustrate the gap between the cultures?
So why did he choose this one for his novel? This is not a report on what he saw in Bangkok that day. (If that statement is even true.)
I don't see this one example of his weird art to be conclusive of his unsuitablility. But it fits a pattern in his art and it fits with reports of his personality from people who know him
"Artistic temperament" is fine for artists, even when extreme. For a politician there's a limit to how much of it is acceptable. Even to "real conservatives".