I think this assumes Gartner just coincidentally offer the right kind of branding and messaging to drive $100M+ technology spending decisions at the present time.

I have a feeling the people running such a successful marketing machine are smart enough to know that over time, decision makers' tastes and preferences will shift as younger generations age into their target audience. Maybe they won't be able to pull it off but I suspect they're well aware that millenials will be listening to something different from their conjoined triangles of success.

Lately I've been trying to reprogram myself to be more self-critical when I run into successful products that don't speak to my own personal tastes - it's really easy to just say "other people are stupid" but I don't think it's usually the full answer. Gartner is kind of like the technology Consumer Reports for F500 executives - it's not really any different from you looking at the rating breakdown for a vacuum cleaner or kitchen appliance back when Consumer Reports was the go-to source for product reviews.

Baby boomer executives are not stupid just because they couldn't tell you exactly how relational databases and Linux work. And it's gonna be a while until insanely busy and established 65 year olds start making significant purchasing decisions based on anime avatar tweets, so Gartner's audience definitely shouldn't be underestimated.