In arguing over the nature of balancing the game, I am often met with a few fallacies, most of them in regards to strikers.
You're taking something away without adding anything
I hear this a lot from people who basically just want to have their cake and eat it too. You can't, for instance, declare "multiple damage rolls per round subvert the basic assumption of how damage in 4th edition works and thus should be regulated heavily" for these people. As far as they're concerned, you're limiting options-regardless of whether those options are balanced or not. Unless you arbitrarily add options, you're somehow a tyrant.
Obviously, the fallacy here is that you're not making the game any different than it was before these overpowered options were introduced in the first place. Maybe rogues needed something more before Snap Shot and Low Slash were introduced (just to give a couple of examples), but that doesn't mean that those two powers aren't disproportionate powerful or in need of nerfing.
He's being a striker-stop punishing that
I get this one a lot. Basically, "he's doing his job." Well yes, of course, the striker is intended to deal damage. But that's completely missing the point that he's not supposed to deal infinite damage. Just how much damage a striker should deal compared to any other class is too complicated of an issue to go into full detail here, but the point is that it's supposed to be a ratio.
Note that the same basic fallacy applies to protecting Pacifist Clerics ability to heal infinitely with Astral Seal and whatnot. The bottom line comes down to the fact that a character's abilities are basically a resource, but those resources come from a limited number of builds. If you have one character that heals infinitely, then you can basically accomplish as much with two characters as you could otherwise with five. Balance doesn't begin and end with everyone "doing their job."
Damnit Tom, you tell everyone to twink and then punish them when they do!
This one is a bit more personal. Basically, it comes down to the assumption that you are, to use TV Tropes terminology, either a Scrub or a Stop Having Fun Guy. Being a power gamer doesn't mean that you can't recognize where the game is fundamentally broken. It also doesn't mean you don't obtain a level of dissatisfaction from interacting with the more broken elements. There's a qualitative difference to optimizing, and breaking the game.