So you went the Wild Card route and then decided you wanted to switch to NCR at the last second.
You can't have everything you want and nothing ever ends the way you expect (or want) it to.
One consequence of going with Yes Man is that once you commit to an Independent Vegas, there is no weasely backpedaling allowed.
The NCR wasn't there to just let somebody else come in and take the Dam (which you did). They weren't there to negotiate with someone who just came in and pulled the rug out from under their feet.
Frankly, if you wanted to help NCR, you should have just done the NCR track and left Yes Man out of it.
Weasely backpedaling? Thats funny. If you knew how to READ you would see I had taken the NCR path and was planning on following it to the end. However I saw the opportunity to take the securitron army away from house for my own means to help the NCR. I just happened to be doing Yes Man missions in the strip to see what I could get accomplished there while going down the NCR path. It came up with the Dont Tread on the Bear mission but I believed Id still be able to use the robots to help the NCR since it was never my intent to take the strip for myself. I just wanted the securitrons, screw house and screw yes man. It was before you talk to the ranger about security for the presidents visit that I left hoover dam and walked to boulder city so I could fast travel again. There I activated the army and sought to use it to help the NCR. I was glad to see they destroyed an already previously massacred fortification hill but dissapointed to see all my speech options made me look like a [censored].
Once more though in case you decide not to read the first paragraph in this post. I didnt want the strip, I didnt want the dam, I only did the wild card missions because it was apparently the only way to activate the robot army after I got rid of house. On top of that I did practically ever NCR mission in the game save for saving president kimball and the final battle so I wouldnt get myself stuck inside of the dam.