From the pilot it was obvious that this was a show about three very affluent South California families. They live in multimillion dollar homes, the the spouses didn't work and stayed at home with their children, they could drop thousands of dollars on flights and five-star hotel rooms, they freely bought gadgets and anything they wanted to, really.
None of this was hidden, nowhere was it said that these families were representative of anything, much less the common person. So all of the above critiques, while sort of valid, are about 11 seasons out of date. They've always been like this, always spent like this, always falling into jobs like this. They're conspicuously rich white/Latino people.
The show is called Modern Family, not Average Family.