He isn't the second most popular romance though, that was Karlach. None of the guys even make the list. According to the romance stats less than 12.9% of players got to his act 3 scene. His smooch button just got hit a lot of times.
Number of times kissed does seem like valuable info to me, though of course it isn't the full picture. I've always wondered how Larian counted "most romanced." Like, does it start in act 1 when you can start "dating," or does it not count until you make a commitment in act 2? If it's simply "X % of players romanced character Y," does that mean that one playthrough with character Y is counted the same as doing 10 playthroughs where you romance character Z? I think that is what it means, so it wouldn't tell us much about which romance people wind up appreciating the most.
The "most romanced" in the stats recently published counts how many people have played the act 3 romance scene for the characters. It does not say if this is scenes triggered in general or scenes triggered per playthrough. I think the kiss counter is very skewed. In another thread it was pointed out that Minthara's kisses were bugged for the longest time. You can also factor in that Astarion not only has a very loud, romance focused fanbase (as shown by the feedback section in general) but was one of the characters who got a new, beautiful kiss first while many of the others were stuck with only their little peck until patch 6. Lae'zel stating that she does not want to be kissed and her kisses requiring an intimidation or persuasion roll in order to become available possibly also has a say in the matter.
I think those stats are good fun, but using them as leverage, especially with the statement that someone is the "second most popular character" which is in no way supported by any of the statistics provided, irks me. And because it slipped past me in the last replay: I want the epilogue hug to remain a hug. I like the hug, the hug is very fitting for Astarion's story - in my opinion.
