Maybe that's lost in the brevity of answers of the people you talked to, but some things I know I only have fun doing when I'm (moderately) good at it. Talking to someone in a different language and having to think about every second word is not fun. Being able to talk and only having to think about a word every few sentences is fun. Same for sports or whatever activity. You think you like it but you're so bad that it's not fun. You try to improve in order to have fun.
Then the goal was all the things the language enables, not the language itself. You want to talk with people who speak that language. You want to function in an environment written in that language.
Even a language theorist researcher who learns a language just to study the language itself with no practical use planned, is still learning it for some other rrason, which is to study it's rules and construction and correlate that with other languages and information systems etc.
Even someone who learns a language not to use it and not even to study it, but merely as mental excercise, has that other reason, mental excercise.
> You want to talk with people who speak that language
No, there's a good chance I can talk to those people in a common language, mostly English. I didn't say my explanation was valid for 100% of the cases, only that it's a bit like that for me and there's a chance other people feel the same.
"I want to talk to people" and "I want to talk to people in their native language when I visit their country" are related, not a complete match. And honestly, I think that borders on overanalyzing. I am sure I am learning languages because I have fun doing it, but I also have fun having mastered a certain level.
