I somewhat agree with you, but I don't think that it was ever his speed that was criticised in 2011. He was overwhelmingly quicker than Jenson, especially in qualifying and unfortunately in many races we never got close to seeing his race pace given the frequent car bonding experience between he and Massa.
The fact is, and it can't be skirted around, he was soundly beaten over the season by Jenson. 270 points to 227. P2 to P5. Being beaten by a team mate so soundly was deserving of criticism, and yes, mainly because of Lewis' high calibre. It's the same reason no one completely freaks out over Stroll being beaten by a team mate, while Seb being beaten by Leclerc rings alarm bells.
I largely agree with you that Lewis gets held to a ridiculously high standard over and above the other drivers, but I still don't think criticism of his 2011 is a good example of that.
He did manage to score a pole and equalled Button in wins. Was also massively unlucky in GPs like Monaco or Hungary where he easily had the measure of Jenson. That's not to say he was better than Button, Button was amazingly consistent and probably drove his finest season that year, but Hamilton had higher highs (that he couldn't keep up throughout the year due to mistakes or bad breaks).