I think its very easy to downgrade a driver when the car he is driving isn't up to scratch, at the beginning of the season when the car was competitive Rosberg was in contention for the WDC and dominated the China GP, in the second half of the season it was very poor.
Also as much as we like with driver rankings car performance comes into play as well, he did well to rank as high in what turned out to be a disappointing car
I've merged these two points together as it seems like you're basically saying the same thing.
My policy on ranking a driver is that it doesn't matter how good their car is. What matters is whether they get the maximum out of their car. If, for example, there are three clearly superior cars and there's one driver in a slower car who consistently finishes 7th, then that driver is clearly getting the maximum out of their car on a consistent basis. Therefore, I'll rank them highly.
I think people generally take that into account when rating drivers. The forum overall ranks Hulkenberg ahead of Webber. Webber has become an established winner over the last four seasons while driving a top car, while Hulkenberg is entering his third year and has no podium finishes. Massa and Grosjean both had cars that were front runners on a largely consistent basis, yet this forum ranked them only 10th and 14th.
Ultimately, when I look deeper into Rosberg's strengths and weaknesses, the circumstances he has and has not excelled in, I see weaknesses in him that I don't see in the five WDCs. That has nothing to do with their cars, but more to do with consistent performance, lack of errors, great racecraft and proving themselves against quality drivers.
There are different challenges in driving different cars. In a lesser car, you'll be fighting to make up for lost time, or sometimes fighting to merely keeping your car on the road. In top cars, you more than likely have to deal with the psychological pressure of being alongside a top team-mate, and you have to constantly live up to the expectation of your team and the media. In both circumstances, it's very difficult to prove yourself.
When Schumacher retired in 2006 he was very much the benchmark, since his return no one can really know what level he managed to get back to, but he wasn't able to beat Rosberg and Rosberg should get some credit for that
Nobody can really know what level Schumacher managed to get back to, but what I will say is that he never made so many mistakes during his first career. And I really don't remember a time in his first career when he struggled to maximise the potential of the car. To say Schumacher was as fast in his second career as he was in his first is to say that the current drivers are clearly quicker than Schumacher's opposition. I find that hard to believe that drivers are getting faster through generations, but maybe it is true, maybe it isn't.
Rosberg gets credit for beating the drivers he has come up against so far in his career. However, he hasn't come up against an established benchmark since Webber in his rookie year (I won't judge him on that as it was seven years ago) so any perception of him is based on whether you believe Schumacher was a good benchmark or not. And IMO, he wasn't a bad benchmark, but he wasn't a great one either.