By your own analogy, blueprints have a very strict set of guidelines on stuff like line styling, font selection, displaying measurements, etc. This is absolutely critical as nobody wants to live with the kind of outcomes generated when there's any meaningful ambiguity in the basic conventions of critical design documents. At the same time, having to hack through a thicket of clashing code style adds to the cognitive load of dealing with complex codebases without offering any improvement in functionality to balance the tradeoff. I've literally seen open source developers lose their commit access to projects over style issues because the maintainers correctly concluded that the benefits of maintaining an authoritarian grip on the style of code committed to the project outweighed humoring the minority of fussy individualists who couldn't set aside their preferences long enough to satisfy the needs of the community.