I wondered the same thing, but I'm pretty sure the lock mfg's have already put the max amount of tensile strength on those spring to insure smooth or consistent keying.
And if they DID make the springs tighter a harder tap would do the trick because it takes VERY LITTLE pressure on the "tap" to bounce the pins.
What just blows me away is that Lock-pick is essentially unchanged for hundreds of years, and them overnight, it's all suddenly obsolete. I already have one bump key for my house and it worked on the FIRST try, I just took my key in and asked him to reproduce it, he selected the right key and I just asked him to cut each position to max depth, -it was a guy at Ace Hardware and he did not even know what I wanted it for. Nor did I tell him.
I put the key into the lock put clockwise pressure on it and tapped it at the 10 o'clock position with the handle of a buck knife and that sucker popped on the first try.
I was able to open it on 8 of 10 subsequent tries, -amazing.
I assume this works on cars too, that's a pity for anyone that doesn't have a smart key or alarm.