Why a safety lever on the CZ 75 instead of a decocker?

[bang bang]

you have alot of questions, but may want to consider TIME. 

why didnt we have electric cars back then and i know there were.    why didnt we have smartphones back then.  same with PCs and many other things. 

Time.  Many things take baby steps (TIME) to get to where we are now. It will be that way 10, 20+ years when you are still asking questions.  Maybe when you are in your flying car, you may ask on the cloud or the hive mind like the Borg, why didnt they have flying cars way back then.

also, its like anything else thats made.  Someone makes a decision on if its blue or red.  Left hand or right hand.  Manual or automatic.  Sometimes it costs, sometimes it the way the owner/designer wants it or maybe the bean counters.  many reasons.  Also, over time things and people change. if you are old enough to remember about cars and safety features you probably have but dont realize that at one time the safety features in your car were not in them and that they were not going to be in them since "safety does not sell" and "no one will pay for it".  It was a common theme about what those that were selling assumed about what us as consumers wanted or not wanted.  No different than what a CEO may "think" the consumers may want even now.  Those are the people calling the shots, but dont understand what we as consumers want. 

For the CZ, note that the CZ wasnt made for you or your tastes or likes. It wasnt even made for the USA.  It was for local consumption since at the time it was US vs THEM. 

If you put TIME into context and your question, you may figure it out on your own and realize that TIME affects many things we have and dont have.

[Walt Sherrill]

For the CZ, note that the CZ wasnt made for you or your tastes or likes. It wasnt even made for the USA.  It was for local consumption since at the time it was US vs THEM.

I'll repeat some things I wrote earlier, because I think you're  off base with a number of your comments and criticisms.

The CZ-76 likely WAS designed  for shooters in the U.S. and the Western  countries on the other side of the Iron Curtain.   I suspect, too, that the Czech government wrongly expected the Western embargo of Communist products  -- that had been in effect for almost 30 years by the time the CZ-75 was introduced -- to end far sooner than it did.   (That embargo had started in 1948 and continued until the early 1990s. )

Prior to the dissolution of the Soviet Union, the 9mm (luger) round wasn't a widely used or available caliber/round in the Communist countries.  The Soviet, Czech and other  Warsaw Pact militaries had no interest a new caliber.  The Czech military had the CZ-52, and the rest of the Warsaw Pact had the Tokarov and the Makarov.

The Soviets had many captured WWII 9mm handguns -- from Spanish Stars, to Lugers, to P-38s -- and they were issued to the East German State Police and Border Guards.  After the collapse of the Soviet Union, many of those guns made their way to the U.S.

Another factor was that private ownership of handguns was very tightly controlled in the Communist Block prior to the fall of the Soviet Union and it's unlikely that the Czech government was hoping to sell to civilians in Czechoslovakia or the adjoining Communist countries.  Things have loosened up a  little in the past 10-15 years, but private ownership of handguns is still not widespread there.

[Stojanovich]

The only handguns I shoot on a regular basis are 1911's and CZ's because they're the best I own for my purposes: weekly steel and bowling pin matches.  I prefer a manual thumb safety on my CZ's.  It makes the transition from a 1911 to a CZ and back to a 1911 a little more instinctive.  Plus, a manual thumb safety allows me to start every relay cocked-and-locked, first shot SA.  Shooters using pistols equipped with de-cockers have to start hammer-down, first shot DA.  I don't know about anyone else but I shoot SA much more accurately than DA!  That said, I like the de-cocking lever on my PCR and P-01 much more than either my Sig P220 or my Walther P-38.