Well, we can be sure of one thing. If nothing is done, then there is a 100% chance he will detonate. I think common sense would tell us then the more that is done that the 100% would start to reduce. ID isn't the solution, it can be part of the solution..
Now you are making a little more sense. If they want to secure the facility, do it in a productive way. Assuming that forcing someone to show an ID will keep them from misbehaving accomplishes nothing. Make the actions worthwhile. Consistently enforce them.
In all honesty, I am in agreement with others that if the facility needs to be secured, and people entering need to be screened, then close the facility. Only allow in those who will be screened, stop the bus transiting the facility.
If you want to keep the facility open, then screen people at the entrance to the buildings they want to enter.
But to tell people that by checking ID's you are "securing the facility" is patently untrue.
You could make that same argument about any public bus anywhere at any time. So would your solution be to check all IDs of everyone getting on a public bus? It would be ridiculous to do do, much as it is ridiculous to check the IDs (and nothing more) of anyone transitting the DFC on a public bus. It's overreach for a microscopic gain (if at all) in security.