Because he is trying to grant amnesty to tens of millions of illegals (criminals) and their families, that is why. It is just natural to suspect that he also told the heads of these agencies (his appointees) not to give out evidence of illegals and/or employers to other Federal law or immigration agencies.
You are jumping to a very unwarranted conclusion. Thinking like "it is just natural to suspect" will lead to erronious conclusions more often than not.
As I told you, that process has been going on a very long time before Bush was ever elected. Bush would have had to tell them to stop doing it, or perhaps change a law, if he even knew about it.
We both need to know the facts of the matter as to the law and how that was done and when. Although I don't know I say so while you pretend to know and you don't.