There is the same offline/AI racing as in Rfactor, so I'm not sure why you had that issue. When I was playing Simraceway quite often there were a lot of people online, though in comparison to a busy iRacing it is quite low on numbers.
Give it a chance though, it is in beta at the moment, many of the cars within the sim are fantastic and I would rate some of them among my favourite in any sim (BMW Z4 GT3, Toyota Supra, Dodge Viper). It makes sense given that there are racing drivers involved with this and they have their own test circuit (sonoma). To me the cars all feel fantastic, very driveable.
It's such a pity that the Evo X is the only starter car, as it is probably the worst car of the whole bunch. Anyway they just added Watkins Glen to the track list along with 2 ovals. In my opinion the graphics look pretty good considering it is Rfactor.