I looked this over and I don't believe it's a scam. I think I know what it's all about.
I used to do this sort of thing, but for cash, not Amtrak points. Amtrak has apparently simply created a partnership with a company doing legitimate consumer research surveys, and you can earn points toward Amtrak travel (which is just as good as earning cash, if you're interested in traveling on Amtrak) whereas if you did this stuff outside the Amtrak arrangement (not necessarily with this company, not sure if they have programs that are not partnered with Amtrak or other companies) you'd be earning cash.
I see they are offering 250 points for joining. My guess (and this is only a guess) is that the points earned for surveys after that point are far fewer than 250. Anyway, I have not computed and have no idea if it's worth my, your, or anyone's time to fill out these surveys. When I used to do it, it became tedious and time-consuming and I was definitely working hard for what would amount to a low hourly wage. The surveys could be about anything - like what kind of orange juice you like, what aisles of the supermarket you walk through first, which ads are more appealing than other ads. Anything at all. I eventually quit because I think I was ruining my eyes by spending so much time on it, and the pay was painfully low. But hey, if you don't mind having your brain picked and the money (or reward in this case) is worth it to you - no harm!
I have not looked over the "pay" scale so I'm not commenting on that. I'm just guessing this is similar to what I already experienced. Usually, there is no "big pay" for this kind of thing. I like earning points, though, so I may consider this. What's a little more eye ruination, right?