As @Michael_Johnson said, this is over the fact that the stock crumbled to half its price, not because of anything Makerbot did. Generally these are nuisance suits that the lawyers hope to secure some fat fees over in a settlement.
I think there is a push for a different class action over the smart extruder too. It seems short of a lawsuit, the extruder communication protocol needs to be hacked.
Perhaps as customers we can think of it as leverage, the company either fixes their bad design or give me my money back or I join in this class action lawsuit and then we will see who is going to have a bad time.