[ghaff]

I've done it. Of course, I didn't travel internationally just for the conference and I didn't need a visa, but I've attended tech conferences on my own--including speaking. Why not? And how many Europeans who attend FOSDEM or Americans who attend Flock (admittedly a lower bar than traveling internationally) are doing so on their own?

ADDED: And people with hobbies/interests like, say, medieval history absolutely will attend a conference/event as part of a vacation even if it has zero connection to a day job.