Basic bolt action question - linear firing mechanism

[BattleRifleG3]

Having recently delved into bolt action rifle design after hanging around semi-autos way too long, one of the distinct differences between bolt actions and everything else is that they don't have a hammer that cocks back and then rotates forward to hit a firing pin.  They have a cocking mechanism in the bolt that cocks and hits the firing pin linearly.

I've thought a bit as to why this is, possibly being less complicated to make, possibly to avoid resistance against the hammer when cycling, but then I thought maybe this is simply the most conducive to accuracy, hitting the primer directly along the boreline instead of swinging up to hit the pin.  That wouldn't account for all the extremely accurate semi-autos out there, but might that be why?

One reason I thought of this was that it would seem more simple to make with my current skills if I were to design one from scratch for a round never to my knowledge chambered in a bolt gun.  Also, this may make a bolt with a shorter throw angle more feasible if it doesn't have to cock over such an angle.  Or perhaps cocking on closing would solve that problem.

In any case, I'd be happy to know why we don't see bolt guns with pivoting hammers, or even external hammers as one might expect from the early days of bolt actions.

Anyone know more about this distinction?

[Lone Star]

Bolt actions were developed in the late 19th century to allow high powered cartridges to be used in combat.  Simplicity of manufacture and operation were foremost design criteria, and once pinfires were abandonded in favor of berdan-primed cases the bolt came into its own.   Few parts means less cost and less to go wrong.  While early bolt actions had their faults, by the time Paul Mauser got around to the M1888 most of these faults were gone....the rest is history.

Accuracy has as much to do with action rigidity and consistent lock up as it does to hammer fall or the lack thereof.  I'm sure that at least some of the accuracy difference between bolts and semis could be due to the lack of a hammer, but really there are plenty of other reasons.  No semi can approach the accuracy potential of the bolt action, although some do come close in light calibers.

[BattleRifleG3]

On each of my bolt guns, one can turn the bolt up and then it will fall open and closed when the gun is pointed up and down.  With an external hammer, it would rub at least a little when opening and closing.  Might this be a main reason there aren't any external hammers?

And another thing I was wondering, might there be any similarities between this and a striker fired semi-auto pistol?