As has been said, you really want them calling when you're ahead unless the pot is already huge, especially when you're way ahead like a set against a flush draw (as opposed to top pair against a flush draw with an over or two).

But also there's some truth to what you say about lower stakes and it becoming a +EV crapshoot, with so many bad calls that the variance skyrockets. Its easier to be a winning player in the long term in low stake games, since the skill of the opponents is much lower, but winning will be less regular and more luck based in a specific session (in terms of needing luck to avoid their outs after making bad calls).