I would have to politely disagree.
Whey protein is and always has been a food supplement. A supplement is something you add to your normal dietary intake in the efforts of achieving a given goal more efficiently. Whey protein is one of the older supplements, but by no means would I consider it comparable to chicken, beef, fish, eggs, etc. It's a food supplement and has its place in fitness and nutrition, but it is still a supplement.
To say it's a food is to say you can substitute whey protein for chicken, eggs, fish, beef, etc as the main protein source for your daily requirements. For example...I can trade chicken for fish for my daily protein intake, this is fine. I will not replace my chicken for a protein shake. I can add it to my meal of chicken, broccoli, and brown rice but I will not take out the chicken and just add an extra scoop of whey.
And though you properly pointed out creatine is already found in beef...it is one constituent of beef. Thats why creatine is a supplement...you a adding/supplementing to what you would normally take in with a healthy diet. By no means could you replace beef for creatine.
Another thing to note, what is safe for one is not safe for another. For example...it is safe for individual A to add a little salt to his fries....individual B suffering from primary hypertension it is NOT ok from him to add salt to his fries. Or how about this...Individual A has full renal function can safely drink 3 protein shakes a day while individual B is suffering from idiopathic renal insufficiency...it is NOT ok for this individual to drink 3 protein shakes a day.
FYI kidneys can play a significant role in hypertension...hypertension is by no means a pure cardiac issue.
The best person who can declare what is safe for any given individual is either a physician or some other health professional, contrary to the tone of this thread, non-medical professionals should not declare what is safe and what is not safe for specific individuals. This is a very dangerous practice.