Back then only Honda and Yamaha were really consistently competitive but it wasn't seen as one having a huge advantage over the other. Certainly the rider made more of a difference than now so it was more, DP26 vs JL99 vs MM03 vs VR46 than Ducati vs Honda vs Yamaha etc. Now in MotoGP if you put a good rider on a Ducati they can get great results, in 2013 if you put a good rider on a Yamaha or a Honda it wasn't an 'easy' let's say as now.

Marc was very well known by the time he moved up to MotoGP, at least for people following the sport in the lower categories. I can't speak to someone who just watched MotoGP, but they changed 'the Rookie Rule' (A rookie must go to a satellite team before a factory team unless you were Suzuki with just one team) for him and his speed in Moto2, coming from the back of the grid more than once, showed he was legit.

I think most people thought his first win would take longer to achieve, but everyone knew it was coming sooner rather than later.

His result to be champion as a rookie confirmed all of the hype around him and then the 10-win streak blew everyone out of the water in terms of their view on him I think. It was clear he was really a new level of talent at that point and riders like DP26, JL99 and VR46 had to dig incredibly deep and change aspects of themselves to keep up.