Martek: Some feel that tying to "physical" (aka "cis") gender is appropriate.
You are using the terminology incorrectly here. The term "cis", in the context we are discussing, specifically means not trans. In particular, a person who is transgender is definitely not cisgender, for the same reason a gay person is not straight, a left-handed person is not right handed, a black person is not white, etc.
If you really need to refer to somebody's assigned sex (that is, the one on the person's original birth certificate), use the term "assigned sex", but keep in mind that that is only rarely necessary.
I may post a rebuttal to more points later on.
By the way, be aware that the word "tranny" is offensive, so it should not be used unless you are a member of the target group (that is, you're transgender) and you are trying to reclaim it. (Notice: That's an "and", not an "or", there.)
a4plz: I've never understood how having separate-sex bathrooms was ever supposed to protect anybody's privacy. The only section of a bathroom which needs to be private is the toilet cubicles, and those are lockable, meaning it's impossible to "perv" on people inside unless you make the ridiculous effort to climb over their door.
If you did run into a trans person, it would only ever be in the hand-washing area, and that's never been a privacy hotspot in the first place.
Fun fact; there actually is a restaurant near where I live that uses this setup; a communal (not sex-segregated) place to wash your hands and two private stalls.
rampancy: I'd have just a smidgen more respect for the people supporting this bill if they just were honest about being homophobic.
I think you mean "transphobic" there.