I realize the motivation isn't practicality, but there are some practical benefits:
1.) Reusable bags can/should be bigger. I can fit in 3 reusable bags what used to take 9+ bags to accommodate. That's 3x fewer bags to carry!!
2.) Reusable bags are sturdier/more durable. Ain't gotta worry about your bag falling apart.
3.) Reusable bags come in many shapes, sizes and styles. They're a great way to show off your personality while you're out and about. I bet they even come in EMAW varieties!
4.) No more putting up with that cancerous growth of wadded-up grocery bags growing out of control under your sink/in your pantry. You know you're never going to use those 3,000 crappy bags for anything.
5.) Use your imagination and come up with benefits for yourself!