Alfista/Alfisti

I have often read in this forum that some people have referred to themselves as Alfisti. I don’t want to go through as a senior teacher, but Alfisti is plural, so I don’t think they say “I’m an Alfisti”, but “I’m an Alfista”. If I’m wrong, and maybe the German name of an Alfista really is Alfisti, I’d be very glad to know the reason for it. I live in South Tyrol, so I speak Italian every day, and an Italian calls himself Alfista. And a pack of Alfa lovers (according to unconfirmed reports, members of various Alfaroodles with pink glasses should have been spotted standing in front of their Bellezze) calls themselves Alfisti …… ;-), which I’ve been counting for about 4 years ….. and quite honestly, an Alfa is forgiven for some sin 😉 So please don’t tear me up in the air, I’ve only asked myself why so many of them are using the word Alfisti, and I’ll use them in the context of course.