I noticed that people who don't like the kind of music I do [by genre in this case] just call it 'Metal' or 'Heavy Metal' they tell me that it just sounds the same, but for a fan like myself I can easily hear the differences. Well thats my opinion
First up, such a good movie!
Next I completely agree with you. I've been studying music for most of my life and will be going on to study Sound next year and as such I've developed an aptitude for identifying the different sounds within everything including music.
I think the people you are describing are very closed minded, musically. In fact I'm sure if you put on two different songs of different sub-genres within their favourite genre they'd be ably to tell you the difference between them.
Think about it, you can't make claims if you're not properly educated right?
My point here is that every genre within a genre within a genre has its slight differences which is what prompted the creation of the genre.
Oh just one thing about Indie music is that when an Indie band gets ore popular and signs a record deal at that point they are no longer Indie.
Indie = Independent. You can't be independent if you depend on a company to put your music out.