Since it was stated by the mods there that droid being a playable race is a restricted topic for new races, these sorts of questions are not that relevant. If and when having non-organic races are allowed, expect there to be answers to all these questions. But only then.
The simpliest reason would be that most people don't want to play them. Also they require special rules (even in the table top game) and were a pain in the tail to keep balanced.
If you REALLY have to have a "Droid" character, why not play some poor sentient who BELIEVES he's a droid? Problem solved there. RP that he got plastic surgery to make himself look more like the droid type he thinks he is. Go with a protocol droid, most of them are bipedal.
Surely not balancing them would be fine, if a droid is strong in any aspect he will go down with any ion weapon, they were a pain to balance in the RPG as everything needed to be equal, since this is also an economic simulation rather than a combat game then leaving them a little underpowered would but why not leave the choice to the player.
You also can't speak for the player base or future players, it would be small minor addition to the combine that stacks possibilities up for the future, even if for now their only difference is they are effected by ion weapons, and can't increase the first box of stats (on character selection, strength, dexterity etc).
Mr. Eagles, we don't need a droid race added because we already have more races than any other starwars game online. And if the Admins decided to change their minds, that's their choice.
Your hounding this is getting obnoxious. They said they don't see it happening for the foreseeable future. Leave it be. Kyria suggested a way it can be done if someone absolutely HAS to play a "Droid" type character.