I've seen this statement on here before and it's not true. It does matter. As you rotate the distributor to compensate you also change the phasing of the reluctor in relation to the pickup. So now you have the rotor lined up with the terminal in the cap but it didn't fire at that time. It fired either before or after the terminal. This can cause crossfiring as the spark has to jump a longer gap. Increased voltage to jump that gap can lead to a weak spark at the plug as the voltage has been used up jumping the rotor to cap terminal gap.
Now on just a regular street car this may or may not be a big deal but on a high performance engine with higher cylinder pressure, low vacuum at idle and high powered ignition systems it becomes more critical. Take an extra minute or two and set it up correctly, you'll save yourself a lot of headaches later.