Well lets see ...
It fits the world,
What does this mean?
No it doesn't. Lockpicks are tools, not consumables. You don't replace a hammer every time you drive a nail in - why would you change your picks every time you pick a lock? A pick is a slightly more delicate tool than a hammer - I could see breaking one on occasion when you fail to pick a lock correctly (or if it's a fancy lock designed to destroy picks), but then you pull another pick out of your kit and get back to work. I own one set of lockpicks - not ten.
it forces us to think at least a little before act,
Again, it doesn't. Lockpicking kits are so readily available (to a really ridiculous degree) that I have never felt like there is a risk of running out of them. And that has been your argument upthread. Thus, there is effectively no cost to failing to pick a lock. The only cost right now is the weight in our inventory, which is at best an annoyance for the player rather than an interesting trade-off for the character.
it was allways working like this,
This is never a good reason to do something. When people say this, it generally means "I can't be bothered to try to make this better".
and its easier to calculate with ...
I have no idea what this is supposed to mean.
