Then they need to go through routine and existing immigration routes to be become citizens - it is not actually that hard to get immigration status in the US. 

Yes it is sad that their parents decided to violate the laws of a country they wanted to live in and bring them in as children - BUT the vast majority of these individuals are no longer children - in fact most are in their late 20s and early 30s, so they have had plenty of time to return to their homelands and apply for US immigration like all the other law abiding immigrants.  But they choose not to and that is their choice - no one elses.

But the major point that most in the MSM is missing is that Obama's action was illegal and unfounded and that Congress (even when in the control of the Democrats) refused to address illegals in the US.  Trump has thrown it back where it belongs (in Congress) and if they don't do anything then he will and his actions will lead to deportations,