Only every experiment that gets readings from instruments with known biases? What the fuck do you think scientific instruments are, oracles? You think they're made of unobtainium and starshine, wishes and wands? Lab instruments can be expensive and delicate and uniform.
Weather stations can't. Lab instruments can be operated in temperature- and humidity- and everyotherfuckingthingelse-controlled environments. Weather stations can't. They degrade, making the instruments behave differently. Conditions change, making the instruments behave differently.
But then, people do tend to judge others' characters by their own.