If you use fatal blows, you are a bad player. If you suck so bad at spacing, timing, and reads so much that you have to pull some scrubby, free, insta-win move every time you're about to lose, you're contributing to the cancer that is infesting this game.
As a Johnny Cage player, I'm pretty much handicapped from the start of every match as my character is garbage. I have to worry about projectile spammers, poke spammers, uppercut spammers, bullshit mixups from Sonya and Scrub Zero, teleports, strings that almost always whiff, and to top it all off, fatal blows. Speaking of uppercuts, crushing blows are the reason why these types of players exist. It is a terrible mechanic that shouldn't have taken the place of the stamina meter.
But back on topic, don't even attempt to weasel your way out of this discussion by spewing catchphrases such as, "get good", or "did you lose?"
It's funny, because the only players who I see using fatal blows the most are those that use casual friendly/easy characters: Jax, Scorpion, Geras, Sub Zero, etc. You'd think that because these characters have all the tools in the world, there'd be no need to cheat your way to victory. Nope, it's quite the opposite. These types of players are try hards through and through. These are the same types of players that will play only 1 match, do a fatality you've both seen 100 times, then leave. He'll possibly send hate mail.
Fatal blows are simply the result of bad game design and need to be removed entirely (it won't). Look, play how you want to play. You bought the game, do what ever you want short of breaking NRS' and Microsoft's rules. But if you use a fatal blow against me, or so much as attempt to use one against me, I'm leaving the match even if I'm winning the set or it's obvious I'm going to win.
You are not worth my time.