This is a sentence in a video：
"But as much fun as they are to find， as beautiful as they are to see, they can't hold a candle to the globular cluster."
in YouTube video: (at 5'45'')
Context: "I love looking at the Pleiads (a star cluster) with binoculars, and M35 at the foot of Gemini is another must-see in the winter throught my telescope. But as much fun as they are to find, as beautiful as they are to see, they can't hold a candle to the globular cluster."
My question is the word "they" in that sentence.
In my opnion "they" indicates "the Pleiads". So there is a problem to understand the first clause correctly. Because I would think this means: They are much fun to find. If "They" indicates "the Pleiads cluster", why he didn't say "they are to be found"?
Could anyone explain how to understand this clause "as much fun as they are to find"?