Which would be why telepaths develop shields, lest they go insane or whatever. Where has it been shown that not having a shield against the thoughts of others was a good thing? If you don't block out the thoughts of others... that is not the norm. One of the first things a telepath learns is how to block that out for a REASON. I suppose... okay, odd analogy, but there's few that suit it well, as it can't be compared to much accurately with every nuance. It's like learning how to control when you crap. Sure, you could do without learning how, but it is not socially acceptable at all. You would suffer negative consequences.
I suppose this would be a bit more like "learning not to crap on other people."
See? There's no way to make a proper analogy, because absolutely nothing is as deep as the human mind. Not even the human body.
And on top of that, there's a vast difference between emotions and thoughts. Emotions are vague impressions. Innermost thoughts are not.
Either way... reading someone's mind without their permission is not a good thing. Not even a neutral thing. That is all I am saying. If someone read my mind, they would shortly find a neverending grudge against their very existence.