To me it doesn't make any difference who is calling pitches, catcher or coach. However IMO the pitcher should have the final say. Maybe not all pitchers, but if you have a good pitcher, he needs to have the ability to throw what he wants.
The reason for this is development. The best pitchers and the best players have good instincts and feel for the game. They know what they have going that day, they know what they are most confident in that day. And not many can be a good pitcher, a real good pitcher, unless you have some intelligence along with this "Feel". Yes, they will make mistakes, but so will the coach and the catcher if they are calling all the pitches. Truth is when pitchers have this feel and when catchers also have this feel, that is when they are on the same page and seldom will a pitcher shake him off.
Now, especially in lower levels of professional baseball, pitches are sometimes called because of development. For example the clubs goal might be to improve a certain pitch like the change up. They want the pitcher to throw a much larger percentage of change ups so they call them from the dugout. Sometimes the pitcher pays dearly when doing this, but the goal is to develop the change up. Also, there are some pitchers that simply aren't able to call their own pitches. Tell them what to throw and they're happy.
Often college coaches call the pitches because they don't have the luxury of wasting games on development. They can't live with lots of mistakes while waiting for the pitcher or catcher to figure things out. They want to take over the thinking process and allow pitcher and catcher to concentrate on other things.
So there are many reasons for calling pitches from the dugout and many reasons to let the pitcher and catcher call the game. But once again the thought process has to be... The coach is always right! Don't clutter your mind thinking the other way. Some call that being coachable! And it is a good thing moving forward.