Because you're intelligent. That money spent on quality food is a way wiser investment. My opinion on BCAA: They are convenient, like whey, but way over-hyped and not required for gaining or even cutting.
1. Are they necessary - No. If your daily protein content is on point, its a complete waste of time. Whole food is always superior. Whey can fill any gaps. BCAA is just more money thrown at the same goal. Pick your form, if you like blue razzle berry flavored shit at 4x the price, fine.
2. Are they neat and convenient for pre-workout, at work before you hit gym, on the go, yes. They dont hurt anything. If you add BCAA with every meal, you will see a marginal increase in protein synthesis. If your natty it "might" matter, if you're on juice, it doesnt mean shit. Hit your protein macros for the day and you are basically maxing protein synthesis anyway on gear.
3. Do you need to drink BCAA before doing fasted training or cardio or else you will "catabolize muscle" - No, complete myth. 100% broscience. BCAA before fasted cardio just spikes insulin and can inhibit max lipolysis anyway. If you want to do cardio fasted, then do it and keep insulin quiet.
4. Can you get the same benefit from a whey shake - basically yes.
Do I still buy these products because I like the convenience, taste, suporting the industry and just plain old entertainment... Yes.