I respect Matt a lot, but why does he seem so anti-data?

I doubt that anything actionable or useful will come of it that couldn’t be obtained by non-data-collecting means.

"Doubt?" Why not just collect it and see if it's helpful? It sounds kinda like a scared/scarcity mentality. Like if we collect it, it's going to be this huge waste. At the very least, it would tell us if it's NOT useful. Or it could be interpreted that he's concerned it'll overrule him, or at least add a lot of fuel for those arguing differently than his vision for Gutenberg (and maybe WP in general).

I can't speak for everyone, but I think most smart people get the idea that (for example) Steve Jobs and his team created the iPhone not based on data or past experience, but on what they themselves wanted and what their gut instinct told them. Just because data might support one thing or another, doesn't mean there's not room to overrule it, or give people what "they don't know they want, yet" as the saying goes. It just means there's more info to make that decision from. And for smaller decisions, it takes away the guesswork and allows the amount of decisions that are made to be cut way down. They can just "follow the data" on that stuff. It makes the decision-makers much more effective at making those fewer, much more important decisions, that they're left with.

I personally would like to see a lot more data across all aspects of WordPress.org. As the previous commenter said, just because WP is succeeding without it, doesn't mean it couldn't be a lot better with it.