No, it is simply honest, which is hard for a lot of people to be concerning Lee, as a person and as a general. Whether Lee was stuck fighting the previous war, guilty of fighting the war as he wanted it to be instead of as it was, or just arrogant, he still fought it stupidly.That is patently false. If he had done so "stupidly", he would have been crushed very early on. The war lasted as long as it did in no small part because of Lee.
I'm really not sure why people seem to take this whole Lee/Grant debate personally. Both were great Generals in their own way. Knowing your strengths and using them to your advantage, while knowing your enemies weaknesses and using those to your advantage are what make a great General.
His successes were almost entirely defensive and his army was outnumbered and under supplied yet he insisted on haring off on doomed offensives. Stupid.
Instead of preserving his army and shepherding his strength he repeatedly squandered it on frontal assaults on objectives that were either pointless or not nearly worth the cost. Stupid.
He focused almost entirely on the eastern theatre and his offensive delusions to the detriment of critical western positions. Stupid.
He pursued a strategy of actively defeating the North, when his most viable option for victory was a defensive plan that required the North to spend more lives and resources than they could stomach to conquer the South. Stupid.
Lee was guilty of overestimating his own strength and underestimating the strength of the North.