GM is slowly getting away from the side post battery for these reasons, plus a couple of more.
Extra reason #1- The internal connection to the + terminal will break internally, causing the vehicle to not start.
Extra reason #2- The plastic cover over the terminals makes cleaning the connections very difficult, as well as helping the accumulation of dirt, corrosion, etc in that area.
Extra reason #3- The seal around the terminals, particularly around the + terminal, will start to leak. This is in addition to the acid that will leak out of the threaded part if a terminal is overtightened, or a bolt that is just a hair too long is used, poking a hole in the terminal.