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 tr

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.