To you, perhaps, I have never used those terms in my game, not in 32 years - they are completely alien to me. I can guess what they mean, but how they specifically apply to a given character build is beyond me. Maybe 'striker' means fighter, I'm guessing, but I think 'fighter' is a much better word, and more familiar term. I can 'grok' that very easily.
Defender, striker, leader, and controller are hard to understand? How? What they're primarily focused on is right there in the name. A defender defends things. What does a striker do? He hits things. What does a controller do? Controls things. Leader's the vaguest of the bunch, to be sure, but healer doesn't quite cover it. And if there was only one class for a role, then a circular definition might work, but that's not the case.
Say the word 'cleric', and I completely understand the meaning and nuance of the term - whether a cleric is a leader, striker, controller, defender, I have no idea, but a cleric is a cleric, he cast's divine spells and heals people. I don't need another term to describe what a cleric is, I know what a cleric is.
But that's because you've been playing the game for decades. Of course you know what a cleric does. To other people not inside the niche, however, saying, "He's a cleric," means nearly nothing, nor is, "It's like a cleric," a good way to describe other classes that may have a similar role in the party.
Trying to come up with four buzz words to describe combat techniques forces us to learn new terminology. Why? Don't you know what a rogue is? Why do you need some tactical title for rogue? The rogue concept is pretty straight forward.
I really am not that put out by learning four simple terms, but if you are just don't use them?
In my games most PC classes can opt to do any job they desire. Sure a fighter is probably better for hitting things in direct combat, but the fighter could opt to change his battle tactics based on whim of the moment. He doesn't nor shouldn't be required to perform some fixed task - not if he doesn't want to. Maybe he wants to control the battlefield or defend the casters in the party - his job changes based on circumstance of a given encounter. By forcing my fighter to take the term 'striker' suggests that's the only thing he can do - strike. My fighters tend to be more versatile than that. You can't pigeon-hole any PC to a specific role, that's up to them to decide.
But, as a fighter, he's still better suited towards being a defender than other classes because of class features, and that's all that roles do. Let me ask you something; why is a class name, something that many people allow to define their characters, acceptable when a general role that class is suited to is not? What line is crossed by dividing classes into things they're innately suited for for easy referencing? I'm just having trouble imagining how you think a fighter is a subtle and nuanced term but as soon as you tack striker or defender onto it they can only do one thing.
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