You have every right to your opinon, but remember, so does everyone else. And while you think led zepplin is overrated, MANY believe the bands you listed are overrated. And as for stair way to heaven, the guitar riff is a classic, the words are very metaphorical, and its just a very good piece of work altogether.
You've fallen out of your love for them, thats fine, perfectly normal. Its like being in love with a person, you just lose connection with it. Hopefully you realize Im not trying to bash you but to let you know that your opinion should stay that way. Theres no need to say a bands lyrics are stupid or this or that. Keep that to yourself because those who like the band will put you on the outside. You're mearly asking to be ostracized because you dont like a band anymore.
Its ok to not like a band anymore, its not ok to degrade them in any way tho. Obviously the song was good enough to make the record, it was good enough to be a single, and it has been ENJOYED for 3 decades now. It has to be a classic at that point because of the sheer number of listeners.
I dont have a personal affinity towards some bands myself, but I certainly wouldnt start a topic about it. If you want to debate about a bands legitamcy, then ask the question, what do you think of led zepplin. You can then in your post say honestly, I used to be a fan but they've fallen from my grace. I've moved on to other bands I feel deserve more recognition.
Overrated is a hard thing to say about anything that's popular. I think paris hiltons looks are "overrated" but at least 75% of guys would disagree with me it seems, so my opinion is nullenvoid at that point. Majority rules in this world society, not the minority.