What a critical article. Basically sweepingly states that the only reason Murray achieved his success last year was because Nadal wasn't around. Gives no credit to Murray whatsoever.
If we actually recount the facts, Nadal was the first of the other big three that Murray beat in a Slam (twice), and Murray wiped the floor with him in their last encounter (Tokyo 2011). Murray's game has only improved since then, quite dramatically, and comments like, "Could Murray have claimed that much hardware with a healthy Nadal playing in those tournaments? It's impossible to say, but history suggests no.", and "Murray has reached the finals of each Slam since Nadal went out. Coincidence? Highly doubtful" are incredibly ignorant and totally disrespectful. Before the USO Murray had never beaten either Djokovic or Federer in a Slam - which he has now done in successive slams. Absolutely nothing to say he wouldn't have ended his recent run against Rafa as well.
Of course let's ignore than Nadal also 'owns' Federer too, and 'owned' Djokovic until his noticeable improvements in 2011 and just attribute Murray's improvements completely to Nadal being injured.
Oh, I fumed over the article, and replied to it too, in much the same way as you've said here. It's totally disrespective of Andy, and only mentions points that happen to fit in with their clearly anti-Murray point of view.
There is no evidence to say that Andy would not have progressed if Nadal had been around. As you say, he has beaten him in slams, and he won the last match between them - well, won is an understatement.
To be honest, the sooner Andy plays Rafa again the better it will be, although I'd much prefer it to be on hard or grass rather than clay. The thing is, it will show how far Andy has come, which some are choosing to overlook, for reasons best known to themselves.
Hopefully Andy will continue to progress this year (it certainly feels like he will) and he'll give a lot of people really bad indigestion as a result of excessive consumption of humble pie.