Not to mention he had an annoying habit of considering his soldiers to be expendable.
Doesn't take much to shoot the wad of an overwhelming force -- then be called a "great General."
Wow. Three contrarian voices in a row. Three strikes. Get a clue & read a bio or something. Grant was a good man of high morals. Was deeply moved by the slaughter of his soldiers but did not let it keep him from bringing the fight to the rebels.
Or perhaps your kind of general is more like George McClennan. Top of his class. Raised a one the finest armies in the world. Thought himself the saviour of the Union & thought Lincoln an ape. Ultimately shown to be a coward, for he couldn't bring himself to actually commit his soldiers to battle, because he was scared.
Lincoln promoted Grant to the rank of General because he was the first one to prove himself a warrior. Win or lose, he fought & didn't stop until somebody won. Made mistakes but never repeated them. He and Abe saved the Union. Where did you learn your history?
A myth. During the entire Civil War, the general with the highest casualty rate among his troops was (wait for it) ... R. E. Lee.
If I remember correctly, Lee came in at 13% dead, with Grant second at 11%.
This is despite the fact that Lee normally fought on the defensive, in a military context where the defensive had an enormous advantage.
Grant, to end the war, was forced to attack Lee's fortifications.
His reputation for not caring is probably based on his refusing to fall back and lick his wounds after a repulse, as all preceding commanders of the Army of the Potomac had done. Grant kept fighting, despite his losses, and won the war. His tactics were the least costly, in the long run.