This thread breaks my heart. I can see both sides.
While I know your trip is over, I still wanted to put out my thoughts in case another parent sees them.
You put a ton of time, money, and effort into an amazing vacation. You wanted mother-daughter bonding, fun, Disney Magic!
I'm sure your daughter wanted it too, but I think there's a few factors in her attitude. First, how much time do you guys spend in the same room with no escape but the bathroom at home? I'm guessing that doesn't happen that much.
So now you both are "stuck" with each other.
She probably is stuck in a weird "people will think I'm dumb/immature if I actually have fun here" mentality. Remember, at 15 kids have an "imaginary audience". They truly believe in their minds that everyone is watching and judging them all the time. At 28, I was able to really not care if people thought my bff and I were crazy singing "Kiss the Girl" at midnight in the Magic Kingdom; but I'm sure at 15 I NEVER would have done it.
Let's not forget some of the issues that plague adults at WDW can plague teens too. Teens have body image issues, food issues, mobility issues; but often are much more embarassed than adults because they don't have the practice in dealing with them.
That said, I was just there with 3 kids (about to turn 10, 6, and 3) and if the 10 year old said it was, "lame, boring, stupid" or that we were "stupid and embarassing" one more time, I probably would have lost it.
I really can see both sides so hugs to all you parents dealing with rough teens or tweens.