Why shouldn't I rely on protein drinks?

If the process work for you- don't change it. 

It is your body and you need to do what makes you and your body happy.

I do drink protein shakes but that because I can't get enough proteins in the day if I do not.
Based on my body chemistry - (blood work) I need 120-150 gr a day to be mid normal.
My body gains weight when i eat too many carbs and the wrong carbs. (that also when I get severe RH - too many or wrong carbs)  I also get really hungry (low BS most likely) when I eat carbs.
So I relay on proteins and fats and some carbs - just enough to make my life interesting and keeps the low BS at bay (that probably means 30-60 gr carbs per day).
I know by now what foods affect my BS and how. And in what combination.
But at the same time I try to avoid starchy carbs. (grains, beans, starchy veggies, bananas etc.) Some more than others.  And even the "good" carbs for me I try to eat together with fat and proteins.

I probably would gain weight on 1600 cal with only 60-70 gr of proteins - the rest is most likely just carbs... and they probably tell you to do low fat.... that would never work for me.

I eat 6-7 times a day. I don't use milk - (too many sugars), and most days I eat protein plus fat rich breakfast. Some fiber also helps. or get protein shake.
Then snack, then lunch, then snack again, then dinner, and LNS... I probably eat more than 1400-1600 per day, but with low carbs (net carbs- I do not count fiber) I not only get really full but also don't gain...
I may have a few chips here and there (but only as a part of one of main meals).
Nuts, cheese, protein shakes, protein bars (quest - high protein) are mine -in-between foods...

But when I have vacation - I still may use bars but shakes are a bit too messy. So I learn what to eat when I traveled. (it is so easy to gain)

Thanks for sharing.
It is working so I kinda don't wanna mess with it. Today is probably the first time in over a year I am under 190 lbs. The protein shakes help me keep the carb monster at bay.

 I think you are wise to find what works for you and question what the surgeon and nut suggest.

I am over 3 1/2 years out and been at goal a long time. like MacMadame, I have a protein drink for breakfast almost every day. no harm I can see. 

I usually have second breakfast (like Hobbits do) a few hours later and that is also OK. 

Hi, I think I should've been at goal but I've been gaining or maintaining for over a year. Just recently I realized that 1,600 calories is simply too much for my activity level....I can't lose.

For the first time in over a year I'm under 190 lbs and I'm excited about that.

It's trial and error I guess. You gotta find out what works for YOUR body.

I positively have to have three protein coffees a day.   Just cant eat enough to get my protein in. Surgeon said if that is what I need to do it was okay.  I am 2.5 years out.  I also eat a lot of yogurt, cottage cheese, and other cheeses most days.  Two bites of meat and I am done.

When I asked the surgeon how big my sleeve is he said he took 90% out so my sleeve is very small.