Except consumerism predates corporations by centuries-- the difference now is that scarcity hurts business and consumption drives profits.
And yes, it is their fault. There is no valid excuse not to be a better person than the media might want you to be... and there's a difference between succumbing to influence and being rendered incapable of making a choice. Anyone is capable of improving themselves, and attributing personal failings to a shadowy entity is counterproductive and to be honest I think it's a large part of why people are capable of feeling good about doing bad things-- because they're not holding themselves accountable for their own destructive actions, and projecting blame onto the corporations.
Yes, the corporations are irresponsible, but the thing is that most of us already know that the corporations are irresponsible and yet we're still buying whatever they make.
Some corporations are integral to modern society because there's simply no way that smaller businesses could ever build cities-- you can't just wake up one morning and say 'hey, I think I'm going to go into the infrastructure business'. You can't go to the moon without a corporation, and without consumerism chances are people would be starving to death a lot more often... if there wasn't demand, production would decrease and you'd be on your own, which unless you know what you're doing and have the means to do it, isn't necessarily the liberating prospect most people think it is.
On the other hand, things like smartphones are NOT essential and in fact make our lives much worse than they could be... there's a disgusting amount of money spent on status symbols and leisure and nasty food that could be otherwise put into more productive things. The problem isn't that corporations exist, it's that they're not responsible enough and there's no incentive to make them more responsible, because that's not where the demand is.
If it were possible, I'm sure the corporations would love to sell us things that would lead to a cleaner better world-- the people running them want to live on a nice planet and improve conditions for everyone as well, the problem is that they haven't found a way to make it profitable and in the meantime the oil industry is using bullshit conspiracies to cover up the fact that they're being completely reckless and irresponsible with the future of our planet, and the same goes for plastics and other types of non-essential manufacturing that move to places where environmental regulations are crap.
If people refused to buy into this shit then we'd all be a lot happier, but it's too much work to redefine our lifestyles in an ethically responsible fashion, and since there's little social pressure to make responsible choices it continues to not happen.
