The whole statement "pros play mostly center ball" is a complete fallacy. What does that actually mean, anyway? Literally it means that they play less than 50% of their shots with spin. That may or may not be true (I lean toward "not" but it depends on the pro). Lets for arguments sake say that it is true, what does this really prove? Some shots need to be shot with english. That may be the one shot you need to run out. Other shots simplify the runout if you shoot it with english, even if it could be shot without. Should you then shy away from the "english alternatative"? THat seems to be what is suggested. To me that depends entirely on the shot, and is not a simple, general answer. So the advice extracted would be "shoot only the exact shots that need english with english". Gee, that's great. How about "shoot every shot perfectly". That's equally helpful, IMO.
Here is what I think: Running out in pool is easier if you think in terms of "lines" than in terms of exact spots (though you may pick a spot on a line as your ideal stopping point). English makes more lines available to you from certain positions, while center ball will have you crossing your line, making more precise speed control necessary. Speed control is THE hardest thing to master in pool. So my advice would be "Choose an ideal line, then choose the english (or vertical center striking) necessary to follow that line." Very often the ideal lines will have you go diagonally through the center of the table. English is often necessary to follow those lines, while center ball will often have the cueball go straight up and down or straight across, especially with object balls on- or near the rail. This is such basic knowledge that it's almost embarrassing to type it out. Learn to play all shots. Then you can run out the hard racks, as well as the easy ones. Play the ideal lines as much as possible, regardless of english required, but use common sense.