When I eat 3 regular, moderate meals each day (1-2 protein, 1-2 carbs) and drink 2-3 shakes (2 scoops whey with water), I'm way harder (no homo) than I am without the protein shakes.
There are times on vacation or when I'm lazy, that I'll stop shakes for a few days. And I get soft pretty quick.
I sure don't buy into the "500 grams a day" bullshit. But 250 a day is awesome, and 50 grams a day sucks.
Now who said anything about 500 grams per day? Nobody in his right mind would recommend anyone going that high, at least not right off the bat.
You increase your intake gradually. If you're stuck, despite consuming, say, 200 grams of protein, you would start by increasing to 250.
When I weighed 189 lbs, I boosted my protein to about 270 or so, from just over 200, or 1.5 grams per lb. of bodyweight. This was back in 1996 (spring semester of college). By semester's end, I reached 210 lbs.