Their Internet connections, if they have them, are typically slow, unreliable, temporary, and can be quite expensive. A slow modem dial-up from home might be charged by the minute or by bandwidth, depending which country they're in and what deal they've managed to obtain. More and more people are trying FreeBSD after realising that there must be a better way than battling with their current operating system. Others go to Linux first, then move across to FreeBSD with a few basic skills and a swag full of preconceptions. They might already have a high level of competency and experience in their old environment, and have to start over again when they get here.
Some people install FreeBSD simply to learn something about unix.
They are students, preparing to be students, or just curious. There are people with new expensive computers who want an operating system that will show off their hardware, and people who want an operating system that won't keel over on an old 386. With so many home users, old equipment is probably more common than it was with the previous newbies. Consider, for example, how often you buy a new car, TV, or fridge. At the same time, we are now seeing people who purchase their first home computer already knowing that they don't want to use Microsoft.