its well known that patches often fix problems but introduce new 1s. stalker for instance wasn't truly stable till it was patched to 1.6 and 1.3 actualy made the game more unstable.
same thing with masseffect, fallout 3 and gears of war. people who were not affected but system crashes on the games release found there games crashing after the so called stability patch which was brought out to help others who's systems were crashing every time they tried to play.
i do agree you should always patch your games to the latest version but sometimes you will have to uninstall it because it isnt quite working the way it should.
then you have the dlc some games like eldar scolls oblivion only work if certain patches are installed. but can often stop working properly when new dlc is applied
or if you install the dlc in the wrong order... knights of the nine and shivering iles spring to mind... they wont actually allow you to play certain missions if you have both installed.
just keep an open mind as far as patching is concerned. and yeah if it aint broke dont fix it can be a mantra, but that wont fix balancing issues