In the Hungarian minor scale we have the following intervals, expressed here in semitones, between the scale's notes (I to VIII):
I II III IV V VI VII (I) / VIII 2 1 3 1 1 3 1
If we take the C note as the base, we have:
c d d# f# g ab b c 2 1 3 1 1 3 1
If we take the trichord starting at position 4, [F♯, A♭, C], we have a chord consisting of a major second (F♯ to A♭: 2 semitones) and a major third (A♭ to C: 4 semitones).
I've been told that this major second is actually considered to be a diminished third. What is the reason for not calling it a major second? Why not accept this chord as the secundal-tertian hybrid it seems to be?