The conduct of military members is defined in the UCMJ and the UCMJ is written by Congress, not the executive branch. DADT is a good program and not difficult for service members to live with.
Really? It's good and easy to live with? It's good and easy for a female soldier who supports her family to have no health insurance coverage for her kids, because her wife gave birth to them and she isn't allowed to tell the military about them or adopt them officially (real example, saw it in a documentary)?
It's good and easy for all the soldiers to meet their girlfriends and boyfriends and husbands and wives as soon as they get back from Iraq in one joyous celebration of not getting blown up, except for the one queer guy whose boyfriend isn't allowed to show up to greet him with kisses and hugs and flowers (real example, my best friend's roommate and his soldier boyfriend)?
It's good and easy that a female soldier with a stateside desk job can get no medical coverage for her aging partner with multiple health problems and disabling conditions, nor can she even introduce her to her coworkers and supervisors, but rather must keep her at home like a secret (real example, my friend's sister and her soldier spouse)?
The strain of being a closeted lesbian cadet at West Point made my high school best friend suicidal, to the point that she was put on suicide watch and was not permitted to lock her door at night so her superiors could come in and check on her. This happened during a period of time that an unknown masked man was coming into female cadet's rooms and molesting them at night. This is good, and also easy to live with?
And it's good because...straight guys are afraid of gay guys? more afraid of gay guys than of armed soldiers being paid to shoot at them? I don't even know that that makes any sense.
I guess the gist of what I'm saying here is that I very strongly disagree with your assertion.