The idea that citizenship is analogous to attending a sports game is absurd. Sports games last a few hours, then you go home. The problem with deporting DACA recipients is that most know of no home other than the United States. Sports games are for entertainment, attending them is a completely optional leisure activity. Many DACA recipients came to the United States to flee violence and persecution, their lives were at stake. Commenters are bringing up this idea that attendees should have 'bought seats' for this sports game. The vast majority of people who are United States citizens are only so because they were born in the U.S. or their parents are U.S. citizens. People do not choose where and to whom they are born, yet some commenters are confusing winning the geographical lottery for something that is earned or paid for. Every serious analysis suggests that DACA recipients contribute positively to the U.S. economy, as every generation of new immigrants has. Sports games are held in stadiums that have a maximum capacity. The United States has a theoretical maximum population capacity, but the country is obviously nowhere close to reaching that.
It also has to do with the simple premise of following and enforcing the laws of the land. As someone previously, and incorrectly asserted, no you don't send them back to make people who did it the right way happy, you do it because if you create a system where you reward breaking the law, no one will follow it.
As a few members here have already stated, the people who followed the law spend tons of time and money doing so. So excusing that because we "feel bad" or whatever, is not only insulting to those folks, but sends a horrid sign to anyone else looking to enter. Who in their right mind would spend years of time doing it the right way and tens of thousands of dollars as well, when you can just run across and then bank on some pity card or sob story life jacket being thrown your way? Shit, the next leg of this whole thing will be, "we can't deport the innocent kids, but we also shouldnt deport their parents because then, OMG, they'll be kids without parents"... Theres no end to it. If you don't enter the stadium with a valid ticket, you don't deserve a seat. Save your money, pay for your ticket, and then you will be welcomed with open arms and enjoy all the benefits and perks of those who are here legally.