Another use of macros is to set up conditional usage--Use ability A if it is available (not on cooldown, in range); otherwise use ability B. A specific example would be for a Jedi Knight to set up a single hotbar key to use Sundering Strike if it's available, otherwise use Strike. This means I only have to use one hotbar slot for the key I'm going to mash to build Focus. An in-game macro system would typically support this sort of programmable macro--don't know that you can do that with an external macro system.