So that's pretty much the stereotypical joke used to laugh at party of the community who are completely clueless players who has no knowledge of how skill balance works and why skills are often not balanced around PvE. I'm not going to go into the special cases where PvE got their own nerfs (spirit bond, protective bond, etc.) and I definitely won't explain to clueless people why skill balance should revolve primarily around PvP.
However, I will discuss the effects these skill balances have on PvE.
That initial quote, though often coming from a naive person, has some basis. Obviously, by using the same set of skills, changes to one area is going to change another. When it's great that skills get buffed (WoH from 100->150), there's often an outrage if a skill gets just subsequently readjusted (WoH from 150->120), and even worse of one when a skill is plain nerfed.
While I am all for PvP balance and spicing things up with new builds in PvE, changing only the shared skills causes a problem: the buffed skills are often not enough to see play in top level PvE areas, while some nerfed skills may result in a weaker ability to farm those areas. It's possible to get new builds, but just with the current ones, you're undoubtedly going to be less effective.
But wait! What about those PvE-only skills? With the previous nerf of splinter weapon, a balanced team is "only" capable of hitting 3 adjacent targets with that skill. Imagine if it were to take another hit (which is likely) to reduce it to, say, the next 1..3..4 attacks. And now you compare it with the PvE-only skills that get untouched: SY, TNTF, EBS of honor, YMLaD, and the greatest of them all, Ursan blessing. You'll begin to notice a bigger and bigger disparity between being able to play a balanced PvE build with one that revolves primarily around PvE-only skills. As more and more skill balances take place and the shared skills become closer and closer to "average" utility, it means PvE-only skills become in comparison, much stronger.
Does this mean we should just screw PvP and not balance at all? No. Not only will it destroy any sort of competitive gameplay, it'll be boring, even for PvE. Sure, some might like running the same thing year after year for the same zone, but others get bored. Skill balance promotes the creation of new ideas, and that's good, at least in my opinion. But with the normalization of all the shared skills to mediocrity, people will be somewhat forced to use PvE-only skills to compete. Even as it is now, if you don't care about lameness, why wouldn't you run Ursan over ANY balanced template (yes, even SY, which falls under the PvE-only category).
As a consequence, the only way to resolve this disparity is to look at the state of the game, and balance PvE-only skills so that people aren't forced to rely on them to perform well. It's one thing to use them to be more effective. It's another to have to rely on them.
What does this come down to? Nerf Ursan

...and maybe balance some other goodies
Oh, and I decided this to write the dumbed down version for people with an iq of less than 60:
For those of you who are too stupid to read the whole thing and can only read one line, what I'm saying is not to just change PvE-only skills because of their absolute power. It needs to be changed based on its relative power to shared skills. For example, if today shared skills allow you to beat an area with 100 points of efficiency, and PvE-only skills boost that efficiency rating up to 120, then when those shared skills get toned down to only 60 points of efficiency, we should not leave PvE-only skill efficiency at 120. We should still make them stronger than regular skills, but not twice as strong (say, to 80 points of efficiency).