Every TARDIS makes the same sound, so they all must be leaving the brakes on. Likely you are supposed to do this, the same way parking your car w/o using the brakes would be a very bad idea. River was probably driving recklessly ("hot dogging"), but if YOUR girlfriend or future wife could safely park YOUR car on a dime using momentum alone, without using the brakes, and YOU lacked this level of skill, would you berate her for this or keep mum about it?