You seem to be obsessed with this minor/major schism?
I’ve noticed you mention it more often lately.
Most (rock, pop, metal, etc) music uses both dear Uwe.
It’s weird to assign either to a genre.
The use of minor and major within one song is very common too. Guess that drives you crazy? 
Of course a song in a major key can use minor chords and vice versa, no issue with that at all. Every major key has a relative minor one and vice versa. That is just circle of fifths basics.
I'm even ok with breaking the rules if it is skillfully done., i.e. putting a major chord where a minor should go according to conventional harmony as Albert Hammond did in
The Air That I Breathe with the second chord - that breaks the rules, but sounded fresh. Or the key change in
Every Breath You Take when Sting goes into the middle eight
Since you've gone, I've been lost without a trace ....
But some of the wanton harmony and key changes that Nirvana and Soundgarden did were (and continue to be) painful for me. It sounds to me like someone doesn't know what he is doing. Some Nirvana songs don't even have a definitive key they're in.
And I'm also not a great fan of playing minor blues scales (rather than major ones) over major key harmonies, it's lazy thing to do, Oasis did that a lot, Angus Young does it too, probably because both don't want to sound like Southern Rock where people tend to play the proper (major) scales over major harmonies. You never heard Molly Hatchet or Lynyrd Skynyrd play minorish over a majorish chord progression.
Of course there are bands and music styles that favor one thing over another! Almost all Reggae and C&W music is in major keys (folk music generally tends to be, whether in Germany or Hawaii), which doesn't mean that they do not play minor chords within those scales
because they belong there under the rules of harmony.
All classic Deep Purple hits are in minor keys, the one exception from the Mk II, III and IV line-ups is
Woman From Tokyo which also contains a nifty key change to the verse (G major) from the riff (E major), a rare thing with Purple.
And nearly all Status Quo hits are in major keys whereby it is noteworthy that Francis Rossi is as a lead guitarist a rare breed as he almost always solos in major scales even when the song is in a minor key (most guitarists do it the other way around, see Oasis or Angus Young). A case in point:
Don't Think It Matters is
a song in D minor with classic D minor pentatonic riffs. Come the solo, nearly all rock guitarists (Blackmore, Iommi, Angus Young, Gilmour, Trower, Alvin Lee etc) would play a minor scale solo, but what does Francis Rossi do? He plays a
solo in D major with aplomb at 02:05:
https://www.youtube.com/watch?v=cWedyugALz4&list=RDcWedyugALz4&start_radio=1That is why the solo part sounds all of the sudden so jubilant and radically changes the mood of what is essentially a dark song. Strictly speaking that is a key change from D minor to D major - it has nothing to do with a relative major key to D minor, that would have been F major, but Quo don't go there, they stick to the D and Rossi changes it from minor to major via the choice of his (D major key) notes. It's a Status Quo trademark by the way and explains why Francis Rossi solos so often sound "happy". Alan Lancaster, the bassist, once said: "
I believe initially Francis didn't know what he was doing, he simply couldn't solo in anything but major scales. And over time it became our trademark and made our music more relatable because he was essentially playing folk melodies over a hard rock rhythm."
By the way, my dislike of Led Zep also has to do with the fact that Jimmy Page had a habit of mixing up major and minor keys and scales in his songwriting. I often find that grating as well, key changes should be used sparingly and best by people who know what they are doing. Albert Hammond did.
Your Thin Lizzy guys wrote a lot in major keys too,
The Boys Are Back In Town (a song with an unusual chord progression for a hard rock number) among them. Phil Lynott would however only rarely break with traditional harmony rules. And they told Scott Gorham what to play because by his own admission he wasn't too sure about the difference either and hence learned his solos note for note, almost never changing them. Have you bought the new boxed set with all the source gigs for Live & Dangerous yet? I have!
