Can learning scales decrease one's aural ability?

It's piano that I'm learning. If often feel many student are blue in the face from practicing scales, and don't feel any better. Too many teachers are only concerned about speed and technique. I feel what happens with learning scales is that you become so used to playing certain notes, that as soon as you hear a note from outside of such a scale, you instead end up playing a note in the scale that's usually right next to the actual note you heard.

Sometimes when I slow down melodies and try to play them by ear, this can happen. When an unexpected note is heard, there's a very weak voice in my head guiding me towards it. But unfortunately the voice of habit in my head, is a lot stronger, and guides me towards the next note in the scale. The problem with this, is that even if you develop your ear and both voices in your head are equally as strong, it's still confusing because your brain is being given two different messages. Always what happens me, is tha it's only as soon as I hit the wrong note that I realise how obvious the mistake I made was.

In other words, if I play fast I'll sometimes get the wrong notes. Sometimes I get them wrong even if they are in the scale... because I'm so used to the pentatonic scales and basic arpeggio patterns. I've a very good ability to play all the correct notes when I play what I hear very slowly. I feel that my muscular memory ability is way way ahead of my aural ability. It makes me wonder if in many ways it would be easier to learn piano as a blind person in certain respects.

In a way, shouldn't an aspiring musician be trained to the sound of intervals before learning any scales. I also think that as soon as someone is introduced to a scale, their ear should be challenged with melodies from that scale. With myself, when I started with guitar teacher, it was always a case learning scales of by heart and then practicing guitar solos by tab. I think it might have had something to do with how he just had fantastic ability to get any melody by hear, and therefore he took it for granted that anyone would have this ability. When I tried to ask him to do ear training, he would only do a little bit, but would mostly deflect and avoid from it.

Is this issue dealt with in music teaching? I'm surely not the first person to mention it. The other issue that I never seem to hear mentioned, is how misleading melodies can be to a beginner. For example, if I hear a melody that's based on a minor chord it could trick me into thinking a major 2nd interval is a minor 3rd. And sometimes in jazz music, a major third interval can be made sound so dissonant that I often think it might be a tritone. I guess it's just a matter of getting used to it. And if anyone's interested, some intervals that I typically mix up would be: tritones with minor sixths, 4ths with 5ths, 5ths with major 6ths, and major 6ths with major 7ths. But I only mix up these intervals when they are disguised within a melody, otherwise I can hear them clear as day.

It's hard to find melodies that follow unpredictable key changes that are very challenging, but that's what I think I need to immerse myself in to improve. At the moment I'm trying 'Fugace' by James Galway.

So does anyone else feel this way? Or is it just me?!

Thanks for reading