Ultimately it's because humans automatically optimize for whatever they measure (observe). What can't be measured, will be neglected.

So we end up with LARGE SWEET BRIGHTLY COLORED fruit with little aroma and lots of poison in it. Because nutrition is hard to assess objectively.

Same with buildings: Huge, square, concrete slabs optimized for energy efficiency, square meters, cost etc. But ugly as fuck, because beauty isn't an objectively measureable thing.

Many other examples. Once you discover the "measureable vs relevant" dichotomy, you'll see it everywhere.