Is your definition of bullish "believes the technology will be widely adopted across society and accrue significant wealth to its owners?" - if so, I think it's very clear how someone could be bullish on AI and not blockchain. You don't have to like AI to see it as an inexorable transformer (ha!) of society and wealth.

Is your definition of bullish "believes the technology is a major net good for society?" - if so, you're comparing two technologies with significant social aspirations that come from very different philosophical backgrounds. While both are techno-optimist, Blockchain is a fundamentally libertarian technology, while generative AI comes from a more utilitarian, capital-focused background. People who value individual freedom above all else will get excited about blockchain and feel mixed-to-negative about AI, while people who want to elevate the overall capability of the human race to the exclusion of anything else will get excited by AI and see blockchain as a parlor trick.