One of my players lamented that Knights can't take the Swashbuckler Power-Up Ultimate Slayer Training - basically a beefed-up version of Slayer Training (and not to be confused with Peerless Slayer Training, which is a broadened version of Slayer Training.)
My response, is, no, it's not a bad thing at all. But I wanted to expand a bit on why I think that's not a bad thing.
Basically, it's more niche protection.
Sean Punch just had a book roll out full of Swashbuckler templates and Power-Ups (and more). Several of them address what might be perceived as weaknesses of the Swashbuckler template vis-a-vis the other combat-heavy templates - the Savage Warrior version of the Barbarian, the Martial Artist, the Holy Warrior, and - above all - the Knight. They also play on the strengths of the template.
Ultimate Slayer Training is a good example of this. It addresses a weakness - Swashbucklers generally aren't terribly strong by DF power level standards. They tend to use weapons with low basic damage bonuses, and usually depend heavily on thrust-based impaling damage. When it comes to stabbing anything but nice, healthy, wholesome humans, this is a weak damage type. Undead, constructs, Things Without Form But With Substance, demons, etc. tend to lack the locations most vulnerable to being stabbed and have Injury Tolerance Unliving or Homogenous or Amorphous Stone to make stabbing pretty useless. That leaves aside swarms. So Swashbucklers are weak against those. A trait that lets them really deal with hit location penalties against those beings where it matters is a nice way to sidestep that weakness. Sure, the demons and zombies and tree-monsters are still an issue, but now you're hell on wheels against their goblin fodder, the necromancer that raised them, and those suspiciously unfriendly druids and animals and whatnot hanging out with the killer trees. You need to hit a vulnerable point to pull your weight, and voila, you do so better than all the rest.
It also plays to a strength - skill. Swashbucklers are skilled and elegant and precise. A trait that lets them be even more skilled and more elegant and more precise makes them better. It takes from "10 out of 10" in swashbuckling to "these go to 11."
Now, take that trait and say, sure, the Knight can have it, too.
How does that make the Swashbuckler special?
You took the bonus they have, the special ability they have, and said, it's for lots of people. Including that guy who spent roughly 95% of his points on just straight-up combat. You've taken something special and unique to a template and moved it into a general power-up. It's no longer what Swashbucklers do better than others, it's just a thing everyone can do well given sufficient points.
Now this isn't to say some book won't come along and give this to Knights. It might (although I think it shouldn't.) But that's essentially a decision to say, this isn't special to Swashbucklers. Even if that happened, would it be appropriate to give Coup de Jarnac or Botte Segrete or Great Void to Knights because, hey, that would be cool if my Knight could ignore armor or launch a tremendously fast attack or flit about defensively like a Swashbuckler?
I'd say no. It encroaches on the niche of Swashbucklers.
You can still make a Knight, give him almost no armor, put on a floppy hat and a cape, take a fencing weapon, and prance around yelling "Ha-ah!" as you stab. You can take a Swashbuckler and give him the heaviest sword you can find, armor the living hell out of him, and make him a straight-up heavy fighter (ahem, Angus McSwashy). But neither encroaches on a niche. Both still leverage what's good about their templates without stomping on the other's niche, simply because they can't access the special benefits accessible through Power-Ups.
GURPS by default says everyone can, given points and proper choices, do anything. Dungeon Fantasy dials that back and says, well, not everyone and not anything. That's fine and that's intentional. It's part of what gives Dungeon Fantasy such a different flavor than a straight-up free-ranging fantasy game run with the same rules base. Tampering with that flavor will change it. It's fine and appropriate to do so . . . but it's one thing to basically abandon niche protection, and another to claim it and use it but appropriate the useful bits from one niche and stick them into another. One is leveling the playing field for all - the other, cementing in the downsides of certain choices but not others.
That's why, in my games, Knights can't take Swashbuckler power-ups.