The ability to read minds apparently is not as straightforward as one might think. It depends on both the emitter of the thought and the reader.
In the anime Kotoura-san, it shows that while the MC can read thoughts, it turned out that the thoughts are devoid of context. In that regard, it is similar to how a text message would go. Example "You are stupid" - the same text message could be an angry message or it could be sarcastic or playful. But taken at face value, one might assume it is an angry one.
In this manga, it depicts that while the MC can read thoughts, it turned out that the thoughts are only partially read (shown by only the text but not the visual). In this regard, it is similar to a radio transmission disrupted by static or a censored message. Example "F**k you" - one could assume the asterisks refer to "uc" but it could as well just be "or" or "ac" etc.
This manga also shows that the reader's own thought can fill in the blanks and distort the actual thoughts read.
TL;DR
Mind reading is complicated; The reader have to (1) determine the quality of the transmission received (full visual or just texts), (2) determine the context of the message, and (3) to compartmentalize which is the reader's own thought and automatic inserts from the actual message.
No wonder mind readers can go crazy.