Last year Button wasn't consistent. Lewis was consistent and fast. He was let down by other factors.
Last year JB was inconsistent, I will give you that, but normally he is fairly consistent in his driving, last year JB struggled with tyres for whatever reason while LH managed to switch his tyres on easily, not that I'm making excuses for JB poor performances.
Button has never been consistent over a season
Even in 2009, for the second half of the year couldnt find any grip and found the car undriveable, even tho Reubens was regularly qualifying on front row and winning races
When he is poor he is the poorest WC on the track, when he is good he is as good as any top half grid F1 driver given the same perfect conditions, his comfort zone is too narrow to sustain a challenge over a season against the types of Alonso.
Even in 2011 he wasn't good enough tho the car almost was, and that's why we had Paddy Lowe? release a press statement saying the drivers collectively couldn't get the best out of the car to beat Seb, before Mclaren withdrew the comment.