Because you are maybe a player that does not relate his personal experience on something like this? Don′t only think about yourself, other players might need this feeling.
Applying an explosive is something i do with my hands and fingers, not only with my knowledge how to let it explode bigger. An agility of 1 would mean that you are able to move your bodyparts like a rotten threepwood, no explosive perk would allow you to suddenly turn into a clock-mechanican. It would have to relate on the explosive skill and agility at last to get such a perk running.
And that is exactly the problem. It allows you to do EVERYTHING what you like in one playthrough instead of limiting you. Sure, you could try to limit yourself, but then if you play the game on a new start with different skills but then you will run into the next problem: you will at some close point realize that it did not really make any difference. It REALLY makes no difference.
Not beeing able to talk to a specific person makes no difference in the result. Not beeing able to pick a lock or not makes NO difference. Not beeing able to hack a computer makes NO difference. And not beeing able to build better settlements makes no difference.
And about the building and settlement skills/perks:
I tried to get trading running for my settlements with diamond city but for some reason nobody knows there that i build up 10 giant settlements with laser guns on their heads. I tried to find some scientists for my settlements for to create me better weapons. For some reason no available scientist has any option like this. The settlements are timesinks, they don′t give you a real efford beside yourself feeling gread building stuff for no reason. They don′t interact with the game itself, they are just fun-cells (for persons that like sims) but have no real reason at all.
The only difference is when you skill your preferred weapon to +100% damage, the rest has only a tiny cosmetic, virtual affect on the gameworld, but nothing that really changes anything.