Antiochus wrote:Ill hammer Kong Weng's point.
By making Sun Ce emperor, Sun Quan would have given a wide openning to his own brothers for the succession of Wu (as if it wasnt bad enough).
Sun Quan outlived all of his brothers.
Sun Shao (Gongli) never could have been emperor because, although he was distantly biologically related to the Sun family, he was still not a descendant of Sun Jian. And it's highly improbable that any of Sun Ce's descendants through his daughters could have any real claim to the throne - they don't have the Sun surname. Sun Shao (not Gongli) and Sun Feng are the only two who really had a chance - and you'll find that, after Sun Xiu's death, there were people who wanted to enthrone Sun Feng anyway regardless of not being a descendant of Sun Quan.
Relatives through a female descendant almost never succeeded anyone in those days. It just didn't happen, and when it did, it was only because the original line had died out and there were no distant relatives to turn to.
I don't feel that Sun Quan intentionally slighted Sun Ce, but I feel that Sun Ce deserved the title of Emperor. Although Sun Jian did much in his life, it was Sun Ce who started Wu and got the ball rolling.
In addition, Sun Quan didn't give his other brothers any sort of title, which to me, is a bit of a selfish move. Even Cao Pi made his younger brothers princes. I understand Sun Lang not getting a position, but Sun Yi and Sun Kuang could have at least gotten a posthumous reckoning as princes.
Sun Quan does, in addition, receive criticism both from contemporaries and from historians for not honoring Sun Ce highly enough. There are plenty who criticize him for failing to live up to Sun Ce's orders: "If there is discord in the family, let not the ashes of the troublemaker mingle with those of our ancestors." Just take a look at Sun He and Sun Ba - or worse, the case of Sun Luban and Sun Luyu.
He also was criticized (granted, after his death) by an envoy from Zhuge Dan, who had come offering submission to Wu if Wu helped him rebel against Wei. The envoy noted, "Prince Huan of Changsha (Sun Ce) did much, and yet, his burial mound is much too small." Sun Quan can build lavish palaces for himself, but his brother gets nothing?
In addition, Pei Songzhi among others criticizes Sun Quan for making Sun Shao (not Gongli) only a Marquis, and that by doing so, he failed to honor his brother fully.
Had Sun Feng been made Emperor, we likely would've seen Sun Ce and Sun Shao (not Gongli) been made into emperors as well, just like Sun Hao did with his own father.