This is absolutely 100% correct. It is kind of like claiming that your kitchen sink is leaking, draining back out the faucet that the water came in through, and putting a check valve in the faucet to prevent it from happening......the fuel evaporates, period. New fuels, and some carburetor designs (carter types) are more prone to this. The solution is to crank the engine on the starter for 4 or 5 seconds if the car has been sitting for while. This allows the mechanical pump to prime the carburetor float bowl, then pump the accelerator a few times to prime the engine, and then start it.
