For those that want longer cool down times you can easily implement those yourself. Don't use that skill again until your predetermined time is up. But in a game about choice you can't say that Joe Gamer can't use the same skill as much as he wants as long as the game allows it. If the developers want it to be usable every ten seconds then it's working as designed. If you want a longer cool down don't use it. For those that want to add things like reagents for spells then you are impacting more than just your game. You are affecting everyone's gameplay. In a game with random loot you want to add something new to keep track of. Say Joe Gamer decides to use his powerful skill on the giant orc and uses all his reagents. Then he goes to fight Arhu's experiment and didn't find any reagents on the way. You are punishing him for his gameplay actions. This is a game about choice and playing how you want. So how can you tell someone they were wrong for using a skill at a certain time? And for those talking about other games that use that mechanic, guess what, this isn't one of those games. Just because the developers liked that game doesn't mean every aspect of it need to be in their game. Again, if you feel like the skill is too powerful for use every 5 turns or whatever, implement your own cool down times, but don't try to change the game to what you want and making everyone else have to play by your rules.
You're basically saying players should have the freedom of making choices that have no consequences, preferably with godmode enabled.