Isn’t it the equal number of H+ and OH- that results in a neutral pH for pure water?
pH is the negative logarithm of the hydrogen ion concentration. Dissociation of water happens to produce a concentration of almost exactly 10^-7 M. Hence the pH of pure water is 7. We call this neutral since it’s pure water without any acid or base added. So yes, dissociation of water gives the pH value of a neutral solution, but the actual value of that pH is experimental. In fact, it’s not true that pH 7 is always neutral. For example, a biochemist would tell you that a sample of a body fluid with pH 7 is slightly alkaline. That’s because the extent of dissociation is temperature dependent. At body temperature, it occurs a bit more, giving a slightly higher concentration of H+, with 6.8 (IIRC) being neutral.