Tier-whoring, inherently has a negative name, and people HATE on this really hard. Using the best tools available to you at any given time is always the best thing to do in a competitive situation. Maybe the best tools to you are the Relentless Jason you put 500 hours into and know every match up. Maybe the best tool for you is your day 3 Quan because you can reliably find a hard-to-blockable set up and abuse it to greater success than your old main.
This is pretty much the thing that made me realise that I'm not created for competitive play, because at the end of the day you will be forced to start counter picking, because game didn't made justice to your favorite character in the meaning giving him all necesarry tools.
I have a very different way of picking a character in a fighting game than other peoeple I read here.
I pick a character based on his story, design (how he looks, moves, acts, etc.) and personality. When I find the one that I have some sort of spiritual connection with, character with whom I can associate myself, I choose him and only then I start learning his gameplay, no matter how hard or low-tired it is. Liu Kang to me is a Superman of Mortal Kombat, a boyscout super shaolin hero who always does good and the right thing, without expecting anything in return. That's how I remember him from original timeline and I hate what NRS is doing with his character in rebooted timeline, but play him still because I know that Liu Kang is a true hero deep inside still, even in that blasphemy version NRS is creating since MK9. I literally can't force myself play as villains, even if they are the only counter picking options and I simply don't like any other character as much as I like Liu Kang in Mortal Kombat series for example and I just can't learn and play a character I don't like, so that's why I use Liu Kang only and it's just kind of personal philosophy of mine - play 1 character per fighting game series. I play more characters only in those games where it is mandatory like KoF13, TTT2 or UMvC3.
My loyalty endures double time because of my character is experiencing injustice from developers both in gameplay and story. And Liu Kang has some very bad match-ups in MKX, where counter picking might be the only option, but I can't go that way, even if Liu Kang vs Tanya feels like 10-0 sometimes.
I'm just a sad example of a player whose favorite character wasn't granted with universal options against an entire roster and I can't force myself to play a character that is absolutely dislikeable to me from story standpoint.
As I said in my post, as long as tier system exists, character loyalty won't bring you 1st places, simply because your character might be a bottom tier.