Yes I do have a lot of sympathy for the 'build it concretely first, rather than just theorize in abstract papers' point of view. There's wisdom in that. But for some kinds of system, there can be dangers of insufficient analysis of attacks.
Building it first means you get eyes on it. Analysing it theoretically first means you might spot the attacks before they're executed against innocent users.
At this point, my own protocol design is sponsored by one person so from a business/economic side of things, it's critical to get a prototype running so the hype train leaves the station and people with fat stacks can throw them at people with Ph.Ds and outstanding reputations as whitehat hotdoggers.
Academic formalism is expensive. For business you need it in as far as it creates trust in the product.
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