I agree that bikes also use resources but they use a lot less resources that cars, SUVs or trucks. Producing a bike costs a lot less resources than a 2ton truck. So many people in my area commute in huge SUVs and Pickup trucks. Just selfish. Gas is till way too cheap here in the US.
Yes I personally care about the environment and this is one of the reasons I bike. Not just to commute, but also for leisure and to shop. I have even built me a cargo bike I can use to run my shopping errands. Not that I want to start a complete car free life style but I want to reduce my car usage wherever I can.