Imo, there ARE bad styles
...and just training with aliveness doesn't cut it.
I know a lot of you will argue that as long as a style trains with aliveness, it'll become a perfectly good/valid form of fighting.
However, I think that even with alive training, there are some styles that are bad.
But let me define what I assume as a "bad" style:
Any style that does not allow you to (restricts you from) fight to the best of your abilities in whatever situation you're training for (i.e. Stand-up, Clinch, Grappling)
Why is this so?
Because, in my humble opinion, once a "bad" style starts being pressure tested, it looks a lot less like itself and a lot more like a tried-and-true style such as Kickboxing, Muay Thai, or the various forms of grappling. Thus, the style itself disappears.
In this way, a good style is the style that does not need to change how it fights in order to fight more effectively.
A great example is Karate. I doubt any of you would argue that traditional Karate does not teach to fight with one's side facing one's opponent. Thus, if restricted to fighting with one's side facing one's opponent, the Karate user will be at a severe disadvantage when compared to another style that squares up, such as Muay Thai.
And under pressure testing, the Karate starts looking less and less like Karate and more and more like Kickboxing. Kyoukushin Karate is the perfect example of this, where you see kickboxers in karate uniforms beating each other up under slightly modified kickboxing rules and calling it "Karate". This is completely different from the traditional idea of "Karate" users "killing" each other with "one punch, one kill".
Thus, I would argue that KK Karate isn't really Karate at all, just an entirely new style of fighting that likes to be called "Karate". (since I'm sure that you can call a style whatever you want it to. Hence Purple Dragon, Systema, Yellow Bamboo, etc)
Now, I'm not saying that a traditional Karate user can't beat a Muay Thai fighter; it certainly is possible. However, the Karate user will be at a clear disadvantage if he chooses to fight facing the side. Or in an exaggeratedly low, squared stance. Or with one hand up and one hand hugging the belly.
TL;DR - A style is bad when it puts its user at a disadvantage and must in essence change itself to something "new" in order to fight in a competitive, full-contact engagement.
And, imo, even Omega isn't an exception to this. (I HAVE to bring this up, since I know he'll call me a dumbass and say he eats souls CMA)
Yes, he fights well. Yes he can kick my ass with Traditional CMA. But in order to fight to the best of his abilities (i.e. competitively), he must use something closer to a MMA/Kickboxing stance instead of the "cat stance" or "horse stance" that most are taught to fight in. Meaning that he's not using just that style anymore. And if you mix styles, you come up with MMA or some mixed crossbreed like Shoto-Ryu-jitsu-nin-do Karate. Which means that the style of fighting is "bad".
Younger generations and their pesky new ideas.