The coup that deposed the first democratically elected president in Egyptian history (the Muslim Brotherhood’s candidate Morsi) was born out of an opportunistic alliance among all the factions of Egyptian society that resent the Islamic bent of the Muslim Brotherhood: the army, big business, the old Mubarak apparatus, the religious minorities (mainly the indigenous Copts), and the young westernized crowds.
The army was indifferent to which ideology prevails but expects a stable and competent government. Mubarak was an old-fashioned dictator but had hired competent people to run the economy and Egypt was actually posting good GDP growth.
Big business was vocal in its criticism of the elections won by Morsi and never quite accepted their verdict. Big business, by definition, was standing by Mubarak, and many businessmen warned Egyptian society of chaos if Mubarak was deposed. Since that is precisely what happened, they feel vindicated and empowered. They were the ones lifting the Egyptians masses from utter poverty, albeit pocking much of the money for themselves.