But my point was more that they've made distinctions between the different types of attacks, so why wouldn't they also make distinctions between bleed, burn and poison as they've done between Force, Tech and Weapon?
For the same reason they didn't make a distinction between elemental damage caused by lightning attacks, fire attacks, and freezing attacks. The distinctions are largely arbitrary and serve only to carry the specific mechanics. Poison, burning, bleeding, freezing, crushing, and all various other terms that are not explicitly attached to mechanics (melee, ranged, Force, or Tech attack type and kinetic/energy or internal/elemental) don't really make a difference. The difference between melee/range and Force/Tech only matters insofar as your primary stat will affect one rather than the other but the difference between internal/elemental and kinetic/energy is entirely arbitrary since everything that affects one affects the other in the matched pair. It's all mechanical abstractions.