A profiler will tell you if sorting actually using a meaningful amount time in your application.
If you go ahead and blindly change your bubble sorts for quick sorts then at best you may be wasting time doing something that has no effect on performance, and at worst you may be making your program slower.
Quicksort is slower than bubble sort for nearly sorted input after all.
It does give you information on where the most time is being spent, but it doesn't tell you what to implement. Without adequate algorithm knowledge you might try a micro optimisation when it really needs a completely different algorithm.
With superficial knowledge you might stick to certain rules without really understanding them. That bubble sort example you gave is a perfect example.
If you go ahead and blindly change your bubble sorts for quick sorts then at best you may be wasting time doing something that has no effect on performance, and at worst you may be making your program slower.
Quicksort is slower than bubble sort for nearly sorted input after all.