Why Avoid The A2 Interval In Harmonic Minor

Why do we avoid the augmented second between 6 and 7 in harmonic minor in voice leading? I always get called on this in my compositions, but I use that interval on purpose. It sounds so expressive and pulls so strongly to tonic, why avoid it? It's not like singers can't sing it now. Contemporary singers should find an augmented second very easy to sing. It isn't hard on any instrument. So why? Why do we avoid the augmented second in voice leading?

Only in very strict harmonic progression of classical harmony there is a tendency to create a bridge between a hole that augmented 2nd delivers when using harmonic scale, because any augmented interval was considered a dissonance. It does sound more natural if you compose in style of Mozart or similar to use rising and falling scale (when going up, augment the 6th degree, and make a natural drop when going down), since that interval sounds curious and a bit oriental when used as a scale material throughout very classical progression.

Did you upload anything that delivers such seconds in general? Which one is that?

http://www.youngcomposers.com/music/4104/fugue-in-a-minor/ My fugue in A minor has several. 

I didn't know the A2 between the 6th and 7th in harmonic minor was a mistake. I quite like it, actually.

Why do you need someone else to validate your desire to use this sound?

I didn't know the A2 between the 6th and 7th in harmonic minor was a mistake. I quite like it, actually.

Strictly speaking it is considered a mistake when it's not part of the melody voice. Since a fugue is mainly based on double counterpoint, you shouldn't use them at all. I'm not sure there is a good explanation for this, it's just part of the way people perceived music during the baroque period. But the point is: If that interval is not an essential part of your compositional idea (if it's not part of the melody voice), there's really no good reason to use it either, it will just sound very exposed and probably make your music sound worse than without it.