I may be wrong, but I do not think this can be laid at the feet of Obama. I’m pretty sure the end of the shuttle program has been planned since 2005 (possibly even earlier).
It was scheduled to be ended, as a new system was being built. The workforce would transition and there would have been a gap that was doable. But that program was canceled by Obama and handed off. We have nothing now and Russia is already raising their "hitch-hiking" prices.
Yes but it was planned for when the follow on vehicle would be coming on line. That got delayed, in part by funding constraints during the 2006-2010 Congresses, and then canceled by "O".