I do find it deeply troubling that so much depends on the discretion of the executive – discretion that is all too easily abused. But that problem cannot be addressed by ending DACA. Even if the policy ends, the executive will still have to make decisions about which lawbreakers he intends to target and which not, and he will still be able to go after only a small fraction of them.
The only way to really put an end to the danger of massive executive discretion is to cut back the scope of federal law, preferably limiting it to cases where there is a broad consensus that the activity in question should be illegal and that the federal government is the right entity to ban it. Then the president will have sufficient resources to target a high percentage of violators, and would be likely to suffer severe political backlash if he refuses to do so.