Counting the number of Executive Orders and claiming that all orders are justified by a given President if he has issued fewer than prior Presidents is complete nonsense. It is perfectly reasonable and consistent with the President's position as an executive to issue orders, so long as they do not interfere with the laws passed by Congress and signed by himself or a prior President. It is the content of the Executive Order that is all-important.
A very legitimate Executive Order would establish an interim policy for the enforcement of a law properly passed by Congress in which a real ambiguity was discovered while trying to implement it or in which an unanticipated situation arose which made enforcing the law clearly contrary to common sense. Upon issuing the Executive Order in such a case for an interim policy, the President should take the matter to Congress and ask Congress to resolve the ambiguity or treat with the circumstance with a new law. His interim policy should be carefully constructed not to infringe upon the constitutional powers of Congress by creating an effect Congress cannot readily re-direct with a new law.
Reagan's Executive Order on immigration was an attempt to implement a new law passed by Congress. That law had the unanticipated circumstance that the children of parents given amnesty by Congress were not themselves given amnesty. This was a truly unanticipated result tied largely to the Cuban refugee influx. George H. W. Bush was also trying to deal with unanticipated results of the fairly new immigration and naturalization law, though on a bigger scale. Obama, however, is doing by Executive Order what Congress under both George W. Bush and under Obama has refused to do. That refusal makes it clear that Obama is acting in opposition to many sessions of Congress and not just trying to deal with an ambiguity or unanticipated consequence of a recent law, which Congress has not yet had time to rectify. Congress has had time and has refused, which is it right to do under the Constitution. A President who defies that right is a despot.
There are even more common reasons for Executive Orders. There are bound to be management issues in running the large executive branch which Congress simply does not wish to micromanage. Examples might be how shall job performance evaluations be written up, what accounting method will be used to deal with a kind of situation, which federal land will be leased for oil and gas development next, etc. One of the essential restrictions of a valid Executive Order is that only federal employees in the Executive Branch are required to take actions in response to the Executive Order. The President cannot order any other American to do anything without the consent and authorization of Congress.
There is a better case, though a weak one, for Obama saying he will not use limited Homeland Security manpower and funding to deport some of the illegal aliens he has decided not to deport. But, it is 100% clear that Obama is not empowered by the Constitution to have work permits issued to those he is not acting to deport. That is very clearly a power that would reside only with Congress.