Speaking of "Green Bags"

I love them.
I have seven.
I from each of the stores I shop (Meijer, Marsh, Kroger and now Aldi's)
Two are thermals (one from Meijer that was the twice the price of the one from Aldi's and not half as well made).
One is made out of old stretchy jeans that was hand sewn while I waited for my prescription at Tucker Walgreens (45 minutes average wait, I hated having to go to that place).

Reasons I love them:
It helps the enviroment.
They don't tear.
I don't have to "double bag" them.
They carry a lot. It's rare that everything doesn't fit in them.
The straps fit comfortably on my shoulders thus saving my arms and hands from angry red welts.
I can carry all of them up a flight of stairs in one trip.

I only have one complaint.
Cashiers.
Before the cashier even starts ringing, I alert them that "I have my own bags". At Kroger and Marsh it's never an issue, because they have baggers.
I served my time as a cashier in a quality customer service driven grocery store in my teens. So I am helpful and I put my items on the counter in the order I want them bagged to help.
Unfortunately at stores like Meijer or Walmart, I rarely luck into finding a cashier who doesn't immediately get an attitude when they see those bags.
After being told once "If you want to use those bags, you need to bag them yourself" (want to guess where?). I decided that I would remain chipper and that from now on I will just offer to bag.

The upside, the cashier can go faster, doesn't smash my eggs and bread and doesn't put shampoo with my produce.


Now here is my rant:
The downside is that I can't watch when something is being rung up wrong.

It happen today at Meijer.
I handed my bags to the cashier and she promptly tossed them on the carousel
and started bagging in plastic.
When I said, "Ma'am I have my own bags", she glared at me, didn't respond and began tossing my groceries on top of the bags.
I bit my tongue and bagged.
After I got my receipt, I found the half-price Cheez-its didn't ring up right. Luckily it was the only error.
The Service Team Lead spotted me (I used to be a merchandiser and she was my store contact) and came over to say hello as I was checking my receipt. I told her that the Cashier needed an attitude check and explained why. She shrugged and said "I know I know, but you know this place."

Wow. I will never get over how bad customer service is now acceptable. And why do Cashier's have such grudges against "green" bags?