I didn't say he was kindly.
He was, in fact, known for firmness, if not harshness:
This is the guy who sent Pickett's division uphill in a suicidal charge against the center of the Union line at Gettysburg in one last, desperate throw.
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But he had no tolerance for cowardice as seen at Charlottesville.
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He was also firm in his determination that the war was over, and nothing good would come from perpetuating it.
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That was not "kindliness".  It was driven by his experience, his sanguine assessment of the situation, and his professional judgment. 
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The quality of his judgment was why he was offered command of the Union armies at the start of the war.  He turned down the offer as a matter of personal duty to Virginia.
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That decision - not one taken lightly - led to the war lasting four years, instead of (perhaps) one, and to hundreds of thousands of additional deaths.
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Nonetheless, he was an outstanding military commander by any standard.