It's simple. If companies pay to display ads on Nostr, mostly bots will view the ads, so companies are worries bots viewing ads not real people, hence nobody will buy their products. How can nostr verify a number a bot or a real human. No way to do this without government ID. Again, ID verification will make Nostr becomes Twitter,  Facebook,  etc. But without real humans, companies will not pay to display ads for bots to view and no sale for product. Bots are the core issue here. Nobody has solved this issue.