It's not shifting blame, it's pointing out they do not exist in isolation. You can put blame on the companies and still recognize that most people make no effort to avoid them, even when they have a choice.

I'll add on what someone said further above:

what would happen if everyone turned around and said ‘you know what, fuck companies that sell drinks in bottles i’m never going to be without my refillable bottle’ how long would coca-cola keep producing 100 billion plastic bottles a year? what would they do with them?

But if James Quincey said ‘fuck it, I’m not producing plastic bottles anymore they’re bad for the planet’ but 8 billion people said ‘oh ok, well we’re still going to regularly buy drinks in plastic bottles’ the numbers of plastic bottles being made would dip slightly but only while Ramon Laguarta rushed to spend the flood of money now coming in to scale up production at pepsi co.