I don't think it's the achievement whoring so much that's upset about lucky nations. It's the people who lack the self control to play ironman without the mode enabled who want to be able to change HOW they play forced ironman.
The issue for me - and for quite a few people here, apparently, if you'd actually bothered to read the thread - has nothing to do with difficulty. If they don't exist the game is easier in some respects, and if they do exist you can find ways to work around it and/or get a benefit out of it. They don't affect the difficulty that much at all.
Lucky nations are not a game balance thing, they are specifically intended for historical railroading. Read the tooltip on the lucky nation setting, it explicitly says that. This is my issue with it, and probably the thing I like the least about EU4: it goes out of its way to make the world in the game end up more or less like the historical outcome. This is pretty absurd, seeing as how the game is ahistorical from the instant you hit unpause. I would be perfectly OK with random lucky nations being allowed in Ironman, but historical lucky nations is just making this problem worse.
Endorsed an achievement hacker? I'm sorry, what? I'm having a hard time believing anyone associated with a game, who designed the achievements with the intention of people getting them legitimately, would ever endorse something like that.
Nevermind the fact that few people actually consider achievements to be worthwhile because of the stupid little trophy or whatever you get saying you got it. People like to actually achieve these things.
The only Great Power that needed 'luck' for its success was Austria, who seem to perform poorly even with lucky nations because the game simply cannot replicate the scale of Habsburg inheritance without being deterministic.
I'd support random lucky nations and, ideally, a sort of 'emergent' lucky nations. If an OPM manages to conquer four other OPMs, or a traditionally less powerful power like the Teutonic Knights or Persia enter the top 10, give them Lucky status and see what they do with it. States that are objectively powerful like France (who ALWAYS surpasses historic France without player intervention) should simply succeed or fail on their own merit.
I personally find a world where Britain, Russia, France and Spain always emerge as the premier world empires quite dull, and love wildcard worlds where Savoy forms Italy and carves up the HRE far more interesting.
Some lucky nations require some lucky bonuses while others don't. For example +1 fire and shock is so incredibly OP for France, who takes Offensive early on anyway. +33% manpower recovery speed is also pretty OP for France. Whereas those are pretty fair bonuses for a nation like Brandenburg or Sweden, even Portugal. I'd rather give France +3 leaders without upkeep than those. Maybe even +2 leader maneuver.
Game is too easy without lucky nations. I'd support "alternate lucky nations" for Ironman, but not lucky nations off.