The problem, as I see it, with the jobs illegals get is that not only does no one (who is not an illegal immigrant) want to do them, no one wants a fair wage allocated to those jobs. Nobody wants the price of tomatoes to go up. No one wants the cost of a new home or a hotel room to go up. No one wants to pay janitorial staff much because it saves on your overhead. It's not just the person hiring them, but in many cases, they're forced to hire illegals to keep their costs down.
I think the biggest problem is that we've gotten used to luxuries. When I was a kid, our phone line was shared by five houses. We had one television in the house, and it was ancient. Our phone was a rotary dial. Our family had one car for a long time, and when it went to two, the second one was a beater. And we were solidly middle class. Home video games and cable TV and computers were pretty rare still. We ate out very rarely, only on special occasions, and the kids (such as I) earned the majority of the money we had (through farm work, for me). We bought fruits and vegetables when they were in season then canned them for later. And this was the 70's, early 80's.
Now, you see very few used cars on the road, used car lots are almost totally gone. My son's friends were astonished that we only had one TV (although it is a nice one) and no cable. Everyone has their own personal phone and computer. People go on trips at a whim, and eat out constantly. More, more, more. With real wages not increasing, and in fact going down, all these luxuries that we've grown accustomed to (and me as much as anyone else) need to be paid for somewhere. Low wages to the people who make them is the logical answer.