While I like that Fighters get a move like this, my immediate question is why can't everyone at least try it?
Because it's something cool for Fighters to do. Anyone can attempt to break things (I would likely use the generic
Defy Danger or
Defend moves, depending on the player's goal, or maybe
Hack & Slash if the goal is offense-oriented). This is just a little something more that befits a Fighter. Other playbooks get their own stuff.
To turn the questions back on you: Why does
everything have to be something everyone can do, unless it's magic? Why can't there just be specialized skills only some people pick up? You seem to be arguing that
literally all people are able to do all physical activities and that's just ridiculous, so I feel like I have to be
missing something in your argument.
Further: if you don't have a Fighter in your game, you can just straight-up take
Bend Bars, Lift Gates as a multiclass move if your playbook offers one that allows you to take a move from any other class. (As noted, DW strongly and very wisely recommends NOT doubling up playbooks in a single group, because it WILL feel very samey. If I had a player who wanted something
like this move but tailored to a different playbook, I would work with them to develop something.)
In 1e D&D every character of any class gets a (generally quite low) bars-gates % chance based solely on Strength. What would work there for making it more a Fighter-specific ability is to, say, give Fighters a -30 boost to their percent roll (low is better here) as a class feature - that way, everyone still has a chance but Fighters are better at it.
Yeah, this dilutes the benefit to the point that it's not actually something I can accept anymore. I want things that are
special about being a Fighter. They don't have to be PERFECT DO-EVERYTHING moves. Just something special that makes being a Fighter
genuinely actually different from being whatever else. Having "you get +30% to Basic Moves" is both INCREDIBLY boring (like...that's straight-up what SO many people
constantly pitched a fit over in 4e, that there were too many
boring numeric bonuses) and gives me, if anything,
negative feeling that the Fighter is something distinct from other things--it doesn't just not stand out, it actively tries to
not stand out.
On a broader note, silo-ing specific abiities like this into classes is fine but making those abiities absolutely exclusive to those classes isn't, where the ability is something that any Joe or Jane could in theory at least have a small chance of doing.
Then we will never see eye-to-eye on this. I want Fighters to have
something, (almost)
anything, that is genuinely actually unique to them and not just generically available to anyone. As noted above, there can be much more loosey-goosey "well, this more or less fits" options for non-Fighters. But Fighters (and, separately and individually, Rogues, Barbarians, Monks, etc.) need to have things that really are special about being what they are. Otherwise they're literally big piles of
actively trying to have nothing notable.