I don't see how playing it would alter his opinion. Most of the things he typed are superficial things one would judge from the first time seeing a match.
and it's not like playing the game once is enough to form an opinion worth a damn anyways.
all he needs to do is go research. There are plenty of places to figure out how BlazBlue is played and once you do that the differences between it and Guilty Gear should become pretty obvious
and for the record there are some pretty huge differences. Like Blazblue's lack of Okizeme(wake-up game) , no FRC's, two button throws, damage scaling(Actually scales down to zero), removal of negative edge, etc