You raise many good points, K. *I say it depends on the individual fragrance, and also on the degree to which a scent either evolves or remains linear. *In some frags, like citrus frags, some top notes do stay through drydown, just because of the much greater quantity of those particular oils, I gather. *It could be a 50-50 love-hate thing for someone who buys a bottle from a department store after testing it and liking the top notes.
For the serious sniffer, yes, top notes are relevant. I (usually) enjoy them in their full glory at the start; it also gives me a clear idea of how, when they recede and linger, they help lead into and support the total symphony of scent.