why does everyone agree that the 70's music is the best music around, and the other decades sucked?

why the 70's are the best time for music
i have a huge love of music and i recently gotten into the 70's bands
and i really like some of it like led zepplin, the doors, rolling
stones, the who, queen, hanoi rocks but thats it, i really dont think
there really that great, more overrated i think,
i was born in 92' and i really think that alot of bands of the 90's
and barely 00's are really good i like
my favorites include pearl jam, stone temple pilots, marilyn manson,
to name afew
i really dont like any of todays current music, slipknot, lady gaga,
and the rest,