Some of the most common “foot-related” injuries that occur in a gym setting (and here I’m using the generic term GYM, meaning not just weightlifting) are (in no particular order), impact injuries like dropping weights on the foot, twisted ankles and slip and falls. The toe shoes that I’m familiar with may offer some help with slipping since they have rubber soles. While not offering a lot of top foot protection, I tend to agree that they may be no worse then regular tennis or even fitness shoes. But lastly, they don’t seem to offer much (if any) ankle or lateral support if they’re being used in more movement based activities (I’d hate to think of someone using them on a basketball court for example – which some gyms have).
So, I guess that my answer would be “it depends…” Sorry.