Again, cover band.
First off, they didn't play note for note covers...they took ideas and in just about every case created a better song. That Spirit song they supposedly ripped off for Stairway to Heaven is laughable. It has about 6 or 7 notes in common, and that's it. Why is it that LZ's "covers" are so widely known and loved over the originals? That's generally not the case as covers go. How good could the "originals" be if just about no one has ever heard them?
Page re-made a traditional English folk song and should apologize for it? Really? Ever heard of Whiskey in the Jar (a traditional Irish folk song)? Arguably Thin Lizzy's most well-known song. Did they have to apologize for it? Nope...and I don't think Bert Jansch apologized for his “Blackwaterside” cover of the same English folk song Page recorded as Black Mountain Side.
When the topic is LZ, it's called plagiarism....change the artist to Kid Rock or any number of rappers and it's just "sampling"...which is somehow considered a different "art form".
I like both the Beatles and LZ, but given the choice, I'll listen to LZ every time because they are rock and the Beatles are pop. If you're impressed with record sales, #1 on the charts and prefer nicely formulated songs to fit a radio playlist, the Beatles are your band.
Oh, but the Beatles put out an album without a name on it. BFD, so did led zeppelin. What's that prove? Word of mouth drives sales? No poo. Someone should tell the record companies!