For me, Yesman is just a failsafe of House, but I get more say during the affair.
I like him, but he dwell on the past and didn't acknowledge the world have been changed.
Keyword: During. He will most likely take the strip after, and do something like kill a few people or something.
He doesn't dwell on it. He keeps Vegas in its former glory, because that was when it was best, and therefore, it is much better than making huts and having cardboard signs saying 'welcome to new vegas'. The future simply is not as advanced as the Pre-war tech and lighting, so it is better if he keeps it in the way which will generate the most revenue, not to mention that it will oo and aww the wastelanders.