I initially understood "bloodier" as in literal blood due to how corpses were handled. In which case I would agree that it was not as bloody. But I do think the term was for body count, in which case they're probably comparable.
My point is that the body count is not an apples to apples comparison, because neither number is precisely known. On the the China side, the information suppression and disinformation campaign started immediately regarding the number of casualties. This is very well documented. I have in my lap the book The People's Republic of Amnesia: Tiananmen Revisited, by Louisa Lim- this book contains lots of evidenced that the body count was underrepresented. Unfortunately, I don't know enough about the Gwangju Uprising to comment further on it.