As long as the tunnel diggers smuggled weapons into Gaza and they were launched at Israel (Kassam rockets, Grad rockets, etc.) it was ok, as long as they did not launch too many or hit a crowded school.
Now the chickens have come home to roost, as they always do.
The Sinai is a vast wilderness of anarchy as it is far from the central government in Cairo.
The Egyptians are now taking out the trash out that has been stinking for 15 years or more. The real problem will be, once the operation is over, will the Egyptians pull their forces and equipment back to a demarcation point as spelled out in the Camp David Accords OR...will they establish bases right snug up against Israel's border...for the next possible war?
Everything is short term thinking right now but what about a time frame a year down the road say?