If we were hunter/gatherers, we would have no choice but to hunt and gather for food.
The argument is not that people are forced to labor, but that people are forced to labor on behalf of others. Which is to say, its the difference between a Hunter/Gatherer living off the land and a King's Huntsman, who is distinguished from a Poacher, in that he has duties and privileges assigned to him by another guy.
You can say there is bad stuff about Capitalism, and better ideas or systems we should do instead, without this coercion claim.
The nature of the Capitalist system is to lay claim to physical property with some threat of violence. It is inherently a dictatorial system, in which a handful of people are afforded the right to claim surplus to sustain and enrich themselves at the expense of their neighbors.
The "bad stuff" is what makes Capitalism a system at all. It is - to crib a joke from Monty Python - the violence that is inherent within the system. If you don't pay your dues to the King, he gets to beat them out of you.
How can you even discuss Capitalism without talking about this innate coercive mechanic?