You don't have to replace the full toilet. There are plenty of options that fit on an existing toilet. You can get simple ones that are just spray all the way up to seat replacements with deodorizers and warm water (they require an outlet). It's easier than replacing your floor and not horribly expensive. Your butt and the environment will thank you.
Is there a functional difference? The company will die or thrive based on the size of the 'eco-hippy' market (well lots of things, but lets keep it simple), motivation isn't really going to change that. I suppose yes from the customer perspective they are buying warm fuzzy save the polar bear feelings, but then the cynical company will tell them what they want to hear anyway.
A bidet for me would involve replacing plaster and floorboards, the payback time would be massive.