The thing is, classic rock isn't a genre! Would you hate a band you like right now if it developed in the 70's, somehow exactly the same?"More Than A Feeling" and "Sweet Child O' Mine" are just two classic rock staples. And they're both hard rock. I'm assuming you don't like hard rock bands then, not all those other classic rock bands (although hard rock and heavy metal do make up the bulk of it). Try digging deeper, like you said. Just a little deeper, and you can find some good bands that still are rather famous.
You say you like 90's punk. Try 70's or 80's punk. Ramones, Sex Pistols, The Clash, The Misfits, MC5, Dead Kennedys, Stooges, etc. They're, from what I'm assuming based on the definition of classic rock, classic rock.
Or try 80's alternative. U2, R.E.M., The Smiths, The Pixies, etc.
Although honestly, these bands are never played on classic rock stations, 'cept U2. But I'm assuming you mean stuff before the 90's.
Oh, and your wrong about the creativity statement. All music is somehow influenced by another genre. Blues slowly became rock 'n' roll, and from there, rock 'n' roll became the biggest musical phenomenon. All genres were influenced by another genre or genres.