So you want to have astromech droids that aren't astromech droids? What's the functional difference between disallowing astromech droids and having astromech droids.. that aren't astromech droids?If there's a logic in your thinking, I'm not seeing it.
I believe the logic here is that a PC is a PC regardless of the species they choose to play.
Therefore, a droid PC should not get what amounts to free gear based on the fact that the PC is a droid. If a human tech doesn't also get to start with a toolkit or slicing gear without paying for it, then it's not particularly fair. Does an assassin droid get a free E-11 rifle for being an assassin?