What advantages does StarCraft have over TA?

StarCraft's Single Player Campaigns missions have more depth.  They include talking pictures of hero units, and different mission objectives.  People actually get feelings for the heroes and their situations.

Total Annihilations plot revolves around the transfer of the human consciousness into a machine, and the war that resulted.  However, they do not develop this plot much during the game.  Additionally the TA missions do include the objective "Capture Enemy building/unit" not present in the StarCraft campaign.

StarCraft has a much easier to use map editor, and the map editor has more triggers and customizable features.

Total Annihilation's map editor comes with more tile sets, and new tile sets are made by third parties.  Additionally, maps can be drawn in some 3D programs, rendered and textured, then imported into TA, making new tile sets, and absolutely gorgeous maps.

StarCraft units can mutate/change into other units, such as two templar into an archon, or mutalisks into guardians.  Total Annihilation has no equivalent nor similar ability.

Some StarCraft units have personal magic (which translates game wise into area damage, and stunning certain creatures, disruption web, mindcontrol.)

Total Annihilation units have special abilities, but cannot prevent units from firing from an area (like SC's Dark Swarm), or being hit in an area without stunning the creature, nor defense matrix.  Additionally, the energy for special abilities comes from your main source, not from some sort of individual storage.

StarCraft 3 different races, quite different.

Total Annihilation 2 different races. Both sides can capture with the Commander unit.  They do not appear as different, but their difference are very useable.  Being a pro at Arm does not make you good at Core.

StarCraft building placement restrictions by race, for example only on the creep, or within range of a pylon.

In Total Annihilation certain buildings must be on water, or geothermal vents.  Buildings have a max and min water depth, and slope tolerance.

Some buildings in StarCraft are mobile.

Buildings in Total Annihilation have much more complex animations, and they alter their foot print when they build units.  However nothing that can build mobile units can move. 

StarCraft has Share Line of Sight built in.  It even allows revealing of cloaked units

Total Annihilation requires TA:hook to do .sharelos. It is a standard mod, but it does not allow auto targeting (you units automatically fire on enemies they see) of enemies if only your ally sees them, but you still can click on them to issue orders.

Units in Starcraft get angry when you click on them too much, and have dialogue they say.

Units in TA share their noises with other units.  Considering the number of units in TA (over 200), most computers in 1997 would not have the storage capacity or memory to store that many sounds.  Additionally, I find the yacking of units sometimes annoying, and turn it off.

StarCraft is more popular.

Total Annihilation has less internet back stabbing.