Not the OP, but I am guessing something along the lines of the following. If you assume that it's your calculation errors that lead to observed discrepancies (

Not the OP, but I am guessing something along the lines of the following. If you assume that it's your calculation errors that lead to observed discrepancies (in eg. speed of light), you won't be able to measure speed of light until you can get those errors below the observation threshold. If you don't even assume that you can get those errors below the threshold, you won't try and you will live happily in belief that the speed of light is, well, infinite.