Let's take Stairway for example...everyone got so hung up over the fact the intro melody sounds similar to Spirit's - Taurus. In a (almost) 9 minute song, it's the 10 second guitar melody that counts...OK. Listen 44 seconds in, that's what it's about.
Now Spirit claimed they ripped them off and all the haters jumped on board and said damn straight, it sounds just the same. Well OK, but Spirit in fact "stole" from Davy Graham(you'd be deaf not to hear the similarity). Spirit didn't give credits as well. Beginning, 22 seconds in, the end..
Now who did Davy Graham steal it from? Justin Timberlake?
Now onto Whole Lotta Love. Ok, some the words are obviously borrowed from Willie Dixon(Muddy's version), so much is true. But the music is completely different.
Little is known that if they stole from anyone, they "stole" from Small Faces(Plant was a huge fan of Steve Marriot and it's obvious in the way he sings it) who pretty much covered Dixon's song, the music, the words and renamed it "You Need Loving" and released it without giving credits.
Not much fuss was given to them. I wonder why... Maybe because they didn't make Zepp's millions.
If you dig hard enough, you can find similarities in pretty much every song...that especially goes for the blues. It's not a coincidence a shitload of artists all sang the same songs(Willie Dixon wrote songs for pretty much every significant blues artist ever). Some put something new in one, the other picked up on it and the music grew and we got blues/rock and we got prog/rock and hard/rock, etc..but it all came from way down south. So if we're gonna give credit to anyone, lets give it to Robert Johnson who did everything before everyone.
You can hate zepp(though i swear for the life of me, I can't understand how you can not appreciate Queen) but don't diss on them for stealing, everybody steals.
I agree with you, there are a lot of artists who didn't get enough credit but that doesn't make popular bands music any less incredible, they made it popular for a reason and defined a generation.