Playing Liu Kang since the very release of Mortal Kombat X and sticking with him through hell and fire that NRS is throwing at him with patches, enduring through everything according to my Nindo of becoming Hokage.
But to be serious, I find character loyalty to be much more cooler and better aesthetically. Probably because I see fighting game tournaments as they suppose to be by the lore of the game. Liu Kang wasn't counter picked during Mortal Kombat tournament in the movie, original timeline and MK9, he went against all obstacles on his own skill and became the Champion. What I mean is that it looks much more entertaining when you enter the tournament with one warrior and you go till the very end with him alone, as if like it would have bene in the story. Player becomes the character.
But of course if you want prise, money and glory, play as the most unbalanced characters, because they win the game. Character loyalty will be quickly overshadowed and forgotten once you will be beaten by counter pick of the character in whose favor this game was made against your main.
Since we are talking about video game, where the strength of your character relies more on how he was made by the developer rather than on your way of using him, character loyalty will take you nowhere if the character you loyal to is mid-tier or lower. Learning your one and only character will not suddenly give him an advantage in already bad match-ups, because the tools that he would need to win in a certain fight are just not in the game.
I mean, everytime I lose with Liu Kang on local tournaments, the first thing people are suggesting me to start winning more is to counter pick somebody else. But I would rather drop the game and sink with my favorite character than become a tier and counter picking whore. If the game can't be won by a favorite character, this game can rot in hell and become forgotten as something serious.
A fighting game where each and every character would have options against each and every character among the roster is a wishful thinking. As long as tier system exists, character loyalty is useless when it comes to winning tournaments.
Pretty much the only thing that saves character loyalty is respect you can gain for sticking with most less used character.
All is relative as well as thing subject. Character loyalty might be good morality wise and gives you a unique charm as a player, especially if you are sticking with mid-tier or lower and he gets not favorable changes with patches, yet you still use him/her only. But when it comes to tournaments and winning? Get ready to die an honorable death, in the end at least you did not counter picked.