Protein consumption comes down to what you need. A competitive bodybuilder or high level athlete needs more protein than a sedentary person or light exerciser. Light to moderate protein levels can usually sufficiently be supplied by the diet.
If you lifestyle and sport require more protein then protein supplements become important. Also the workout window also makes protein consumption from supplements sources important.
The answer is it all depends on the person and if you can get your protein from food then more power to you. However, from my experience I have found that most people do not get enough protein in their diet and therefore can benefit from a protein supplement.
One final point is the amount of protein is important but it is not as important as the quality of protein and the ability of your body to use the greatest percentage of the protein you ingest. So my rule of thumb is worry about protein but mainly worry about the quality of protein from good lean protein sources, dairy and eggs and if you need it good quality protein supplements.
How do you know if a supplement is good? This is way to complex to answer here but the simple answer is follow the integrity of the company. If a company has a good standing and good reputation then ALWAYS the company makes a good quality supplement.
Always consult your coach as they can help you with your protein consumption, amount and timing.