[heheikkeseher]

My attempt at explaining it;

NH2 would be more reactive than H2O because nitrogen has a lower electronegativity and would more easily attack?

[pgk]

Reactivity towards what?

[Babcock_Hall]

I sometimes think that because electronegativity is taught early in the chemistry curriculum, that students want to use it to explain everything.  Electronegativity is useful to explain some phenomena but not others.