Every book, no matter how good it is, is linear. It's not like the reader has any kind of influence on the story. But that doesn't mean it's not a good book.
Same thing goes for games - it may be linear, but that doesn't mean it can't tell an amazing story. Some games choose not to be linear, S.T.A.L.K.E.R. for example. That game has like six different endings. Which is really cool too.
Linear or not, neither is necessarily "better". Both can be amazing.
Anyway I believe the devs are currently talking to SecuRom.... if they get rid of SecuRom or any other kind of mallware in the next shipment or patch, I will purchase it. If not, they've lost another customer. One of the many. Shame really, because the devs deserve to get supported for their good work on the game.