They use plastic bottles instead of alternatives. I'm not saying consumers don't have responsibility, but it starts with coca cola ordering/producing these bottles to package their product.
Then why are they being singled out? Plenty of other companies use plastic just as much in their products.
Because they are the biggest offenders, for three years running. Rather than trying to target the abstract 'beverage industry' as a whole, it's much more pragmatic to just look at the biggest players. Besides, they tend to set trends so there's a little bit of top-down influence as well in being the industry leader.
They have the biggest brand. Brand shaming could lead to change not just them but ripple effect on other plastic using companies.