Their arbitrary nature is designed to consolidate executive branch authority that can be welded as a weapon against corporations that might consider supporting his opposition in the future.
It's a classic fascist ploy, and is further proof that executive orders should be banned. In America we do not have kings who rule by decree, or at least we should not..
Executive orders that violate, or direct the violation of, existing law are illegal (or, at least, without legal effect) to the extent they do that, but whether or not a particular order meets that description is frequently a matter of dispute, which can end up in litigation.
But now we run into the question of What is illegality without ethical-centric courts?
That's the theory anyhow. As you mention, the courts now just obey the executive rather than acting as a check and balance as intended.
The period between the inauguration of the first President under the US Constitution (April 30, 1789) and the first formal executive order (June 9, 1789) was 40 days, so I have no idea what you are thinking of.
EDIT: It’s worth noting that the first Act of Congress was only signed into law 8 days earlier than the first executive order was issued, so for most of the time before executive orders the executive had no actual laws to execute.
Sort of. The executive order was originally used for routine administrative orders. Later their usage expanded, but they were still required to be based on either an expressed or implied congressional law, or the constitution itself.
Now, presidents use them to invent law from scratch as Kings once did. They often do so under the flimsiest of pretense, if they bother with pretense at all.
It is this type that should be banned, or more accuratly: existing laws should be enforced.