It demonstrated to the Islamist's that playing by the rules is pointless. Why go through all the trouble of actually selecting a candidate, campaigning and getting elected if they're just going to be taken out of power by force anyway. You will note that the Salafists have already withdrawn from the coalition and have formed a war council.
As much as I disliked the message and the direction that the country was being taken, there should have been some other way to change the direction the country was going without resorting to a coup.
What happened was about as anti-democratic as possible.
Just imagine if after Mubarak had been forced out instead a completely pro western government has been elected and a year in the Muslim brotherhood had millions out in the street protesting and suddenly the government was forcibly removed by the military.
We'd call it a coup. We'd be freaking out that the Islamists were taking over in Egypt.
However because we didn't like these people in the first place we'll all argue that this was positive change and that Egypt will be better off for it. I don't believe it will be.
What happened here was a combination of many things.
1. People in the street not understanding the democratic process. If you don't like the president, you work to get a recall election going, not call in the military.
2. Morsi was too busy pushing his social agenda and not focusing on the economy. Had he focused on getting Egyptians back to work and pumping up the tourist industry he'd likely still be in power. However either blinded by his ideology or beholden to the ideology of those around him, he went off on a tangent trying to implement an Islamic state.
Now with Morsi supports being killed by the dozen, how long is it going to be before there's a call to take up arms. Then they'll be a call from the other side to take up arms
In a nutshell, I see a civil war coming in Egypt and it's going to be pretty. It'll be YAMENOF (Yet Another Middle East Nation On Fire)