It's funny, but there's really three analogies I use to explain the "whats" and "whys" of the hyperloop concept, and one of them is a roller coaster (the other two being the "super-high altitude airplane" analogy and the "building a pipeline" analogy).
Compare a roller coaster ride with going on a train. Are roller coasters built suchly that you have to wait half an hour or more between rides because they haul many hundreds of people at once? Do you have to spend 5 minutes boarding and later 5 minutes disembarking because of the scale? Does a pilot have to take the controls to maintain spacing and occasionally handle the risks of merging traffic and the like? And the tracks massively heavy and expensive to support these giant roller coaster cars?
No, of course not. Roller coasters are well optimized. Roller coaster cars are small, maybe two dozen or so riders at once. Because of this, they load and unload quickly. They're predominantly computer controlled with only a bit of human "central control" to send craft on their way and the like. They're all "expressways", no intersections, so all the computer has to do is make sure that it's not too close to the cars ahead of or behind it. Because the cars are small, the track can be made light, which makes it a lot cheaper.
Hyperloop implements the roller coaster paradigm to a tee.
That said, the current stage they're at, I wouldn't put people on it. They need to make sure that things are going to go as expected. Most of what they're doing is mature tech, but a few of the things, like the air-bearing skis, are going to need a lot of testing to prove their reliability. Right now they need a proof of concept and to iron out the basics. The next step up, where they have to prove the predicted reliability, repeatability, throughput, economics, maintenance etc, that would be more of the stage where an amusement part ride would be a possibility. Though I'd personally prefer that their next testing stage be built as something that, if it goes well, one could just expand into an actual hyperloop route. Maybe several dozen kilometers here - that should be enough room to accelerate up to top speed, coast a bit and deal with some curves and the like, then decelerate back down. And if it works out well, I have trouble picturing that some Vegas casino magnates wouldn't pay to link it up between them and LA. 6-ish billion dollars to enable millions of people in the LA area to pop over to Vegas in half an hour for $20 and unload a couple hundred dollars in the casinos? The amount of additional traffic they'd get would pay that off in a heartbeat.
Although... hmm, you know, they designed Hyperloop to limit passenger vertical acceleration to 1G and lateral acceleration to 0,5Gs, for reasons of passenger comfort - but not reasons of structural integrity or acceleration capability. So you know, even on actual routes, they actually could potentially let people purchase tickets to a... ahem... less G-force limited experience. ;) It'd require more car spacing, so the tickets would cost more, but when your base price is only $20... Plus, you'd get there a little faster. ;)