Trump is virtually throwing thousands of pages of the CFR and USC into the trash because he believes that the statutes and regulations are arbitrary and unfair to businesses. So, when talking about whether DACA recipients should be held to the letter of the law, it is only fair that immigration law should undergo the same scrutiny as environmental laws and other areas that have been the subject of swift executive actions.
US immigration laws are incredibly unfair and the US immigration system is unconscionably slow and unfair. The US limits the number of green cards (legal permanent residency) it issues by country. That means that it can take up to two decades to a green card common from Mexico, but as short as ninety days from a country like Sweden or France where there is little demand because most people get in the country through an employer. But temporary work permits are very easy to get because of the need for farm and seasonal labor. So, hundreds of thousands of people come to the US from south of the border to work every year on temporary work permits. Some overstay there visas and do not go home because they can make so much more in the US so that they can send a more money home than they could ever make in Mexico. Instead of waiting for 20 years to get a green card, they just live as undocumented or illegal immigrants. Eventually, their family wants to reunite with them and crosses the border illegally. They stay and have children or bring children with them. Thus, the current immigration process from south of the boarder is completely unfair and unjust.
You can ignore this injustice and ship as many people back over the boarder and build a giant wall. But that will not stop people from coming back. For most people who cross the boarder illegally, climbing a big ladder and shimmying down a long rope is one of the least intimidating obstacles on the way across the boarder. Getting raped by Coyotes (the human traffickers, not the animals), being held for ransom, being sold into sex slavery, getting killed by drug traffickers, or dying in the desert or a hot container truck are all far greater concerns than having to climb a wall (or going through a tunnel under the wall or riding in a boat on the ocean to the US coastline). All you do by upholding an unjust law is spend billions to uproot people, causing economic chaos in immigrant communities and resulting in the vast majority of the immigrants coming right back over the boarder. A big nothing burger.
Or you can recognize that the law is unjust and do something about it. If you get the wait time to get a green card down to a year, illegal immigration from south of the border would all but stop. No one would want to risk rape, torture and death crossing the border illegally when they can just navigate a reasonable immigration process. Granting amnesty to people who came into the country illegally would get 10-12 million people out of the shadows and into jobs where they pay their taxes.
People losing their factory jobs in the Midwest are not waiting in line at Home Depot in Austin, Texas to get day labor work. Illegal immigrants are not taking jobs from citizens. They are doing the work citizens refuse to do.