Your question is reasonable: Why take advice from a guy not looking to get big? Well, I spent quite some time trying to get big and got pretty big, albeit a bit chubby. I did use PWO nutrition when I was obssessed with all this. And looking back on it, I wouldn't have used it or used less of it.
However, if you keep your calories at the appropriate amount, and you believe that PWO nutritioin will help you, then have at it.
From what I know about nutrition now, I can't see how pre-workout nutrition is so crucial considering it can take hours for a decent sized meal to be digested. So it's not like there aren't any amino acids or carbohydrates available during a workout unless one waits hours and hours to work out. As I've said before, it depends on how long someone hasn't eaten until they start their workout.
And if I get home ten minutes after a workout, shower, and eat a meal, I don't see the point in guzzling a shake after my workouts.
If people DO see DISCERNIBLE results from PWO nutrition, then they should continue. I don't know everything, I work in healthcare for the time being, and it's not like I have a roster of clients in a sports nutrition practice.
There are varying degrees of fitness, just like there are varying degrees of bigness and strength. Sure, the need for supplements is lower considering I'm exercising a measly 5 hours per week and eating a measly 2,500 to 3,000 calories a day. But there are strategies I can take to get even more fit, nutritionally and physically. So there is use to some things even if general fitness is sought.
The thing is I choose not to do some things because of the limited reward they provide me. I'm at a certain level of fitness I'm happy with, and it's not outrageous. I'm just in shape and healthy. I choose not to be in EXCELLENT shape and settle for DECENT shape because I came to the conclusion that excellent shape doesn't provide me with things most important to me and displaces my resources that can be invested in things more important to me (time, money, other interests, socializing, time with family).