Nah
Liu Kang needs to retain his personality and stay good. I mean, he's the main hero after all, right? No need to change up his personality just to make him more popular or well-liked amongst fans. There are much better ways to capitalize on his potential than that, speaking of which...
If/when they revive Liu Kang in MK10, I'd like to see them make him become a renegade Forces of Light member; by that, I mean he could rebel from Raiden and go off to form his own Forces of Light (this is where I would like to see new characters come in, btw). The group would be mainly formed to defeat Quan Chi and force him to resurrect all of the good warriors that were killed during MK9 (especially Kitana).
What I like about this idea is the conflict that would arise between his faction and Raiden's faction and the parallels between Raiden's approach and Liu Kang's approach to things. Liu Kang's strategy is more straightforward, where his main goal is just to beat all of the bad guys until they get to Quan Chi, unaware of what the Netherrealm is planning, while Raiden, sensing much bigger things to worry about to come (Shinnok), takes more of a tactical approach by focusing on rebuilding his forces and trying to convince every one he can around him (including his enemies) to join his cause in preparation of said threat. So, basically, Liu Kang is more driven by personal matters and emotions so he acts more on impulse as opposed to Raiden who is more driven by the need to ensure the safety of Earthrealm as a whole. This was sort of touched upon in of MK9, where Liu Kang just simply wanted to defeat Shao Kahn while Raiden wanted to surrender to Shao Kahn knowing that the Elder Gods would intervene when Shao Kahn would try to merge Outworld and Earthrealm, so I'd like to see this explored more fully this time.
Also, where the conflict between the two forces would come in is the recklessness of Liu Kang's forces affecting the plans of Raiden's forces. Let's say Raiden wants to recruit some of Shao Kahn's former minions to their side, only to find Liu Kang and his forces beating the shit out of them in an attempt to get answers out of them on where to find Quan Chi (since they don't where he is). And since the team of Liu Kang's is a product of Liu Kang's frustration at Raiden, you could say that there would be a one-sided rivalry between he and Raiden.
So... yeah, that's that
*goes back into the shadows*