If it was about the environment they wouldn't have included a charger either, yes. (They wouldn't sell disposable in-ear headphones either. No exchanging batteries) But if it wasn't about money, they would've added a coupon/code to buy a charger because the product is useless without one...

Just because the actual action can also be spun in q environmental friendly way doesn't mean the company actually did it for that.

They didn't want to include a charger and just used the environment as an excuse so they can argue all criticism away