One deciding factor seems to be that one third of Stubb voters say they vote for him at least partly because of Haavisto's homosexuality. That's actually very similar to the share of those who named it as a reason to vote for Niinistö over Haavisto in 2012. So based on that, not much has changed with more conservative Finnish population in 12 years, even though we now have legal same-sex marriage (the law was actually approved in 2014 when Stubb was prime minister).
That's very depressing, especially considering how close the result was.
