I don't know that I agree that "telepathic" is quite the right word - Su'Kal was a polyploidal mutant whose genes were affected by the dilithium in the environment - a sci-fi extension of a real genetic phenomenon that can occur when extreme environmental stresses are present. The explanation they gave was more scientific that many of those that we've had across the history of the franchise.
At the end of the day, if it doesn't work for everyone, that's fine - I personally think it's a very TOS/TNG idea, sort of a "Charlie X" by way of "The Survivors", and I think it's pretty obvious that the producers wanted the source to have a "human face" if you'll forgive the expression.