Great topic. For me golden age comics are like magical objects. They have their own spirit, relics of another world, etc. Signatures totally break that spell for me. Although I have favorite artists that I collect and have big passion for, their signature means nothing to me. And I enjoy seeing the writing done by people who owned/grew up with the books, for me that adds to the magic and spirit, but having someone 30 or 40 years later, scrawl their name across the cover with a sharpie, that doesn't not add value, it diminishes it.