Oh no, not Jerry Ward....
Protein = All BCAA and EAA. If you eat some in a reasonable time before a workout, it'll be broken down and available during training. Same thing for carbs (Lactose in Milk along with your Oats, Oikos Triple Zero Greek Yogurt and Grape-Nuts, Fat Free Refried Beans <--- my PrWO meal). Lifting weights does jack all to deplete Glycogen anyway - you (the average 90 minute/day lifter) have enough in your Muscle and Liver +100. Barring gastro issues, I think all the different types of carbs are a "concentrating 90% on the 1%" type of thing when it comes to real world performance.
Now.... that doesn't mean an Intra is a waste even if you eat though. Why? Well, I'm one of those "Just let me answer one email" guys before gym time... and 2.5 hours later I finally start warming up. Am I going to eat again? Nope. So
it really depends on how you eat and train. If you can 100% hit your main working set 60-90 minutes after your PrWO meal, then they are a waste. If not though, they may have some merit.
Even then, they aren't "Game Changers" IMO - I've failed lifts on both water and Intra's with a bunch of fancy "Ergogens" in them. Test them yourself - try some Vanilla Whey/Casein in Gatorade vs. an Intra on the same lifts back to back. Cancel out natural progression (i.e 1 more rep or 2.5lbs added, etc...) and see what the difference is. Experimenting is fun. Spending $30 once, could save you from spending $30 for the rest of your lifting career