Only because of his age.
Carrick's controlling games this season like Alonso was in 09. Not saying he's as good a player, I doubt even United fans would say that, but in terms of his contribution to a title winning side (probably), he's been top tier.
Because Real Madrid aren't offering £30 million doesn't mean he isn't world class, I think this season (and parts of last) he has been. I also think Gareth Barry's similarly underrated; he acted as the lynchpin for a team that won the premier league, yet people treat him like he's shit on their shoe.
There's a reason Rafa wanted Gareth Barry, whilst like Carrick he may not be as good as Alonso overall (and specifically Alonso post 08), but he can function in the same role as Alonso to a standard required to dominate games consistently, and enable a team to win titles, and competitions.