No, it depends on leverage. If you've got the most leverage, the relationship will be pleasant. If you don't, the relationship will be abusive. Just like everything else in capitalism. Supply/demand balance and friction matter far more than how "nice" your customer/employer is.
The distinction is crucially important: if relationship quality were an independent variable, everyone would be able to find decent relationships by hopping between jobs every now and again. Unfortunately, that's not how it works. The market determines what employers can and can't get away with, so someone stuck in a crummy relationship is likely to find a bunch of equally crummy relationships when they go job shopping.