People living beyond their means doesn't stop at MM price range. They're everywhere.
You are right. Pretenders are everywhere.
Now, during the boom times, because prices were so high, there were tremendous incentives to create housing supply to cash in on the high prices. Supplies were added in downtown SD, 4S, Carmel Valley, Temecula …
Since all of San Diego county & southern Riverside county iis effectively in the "same market", supply added to downtown affect prices in Mira Mesa.
For example, the condo glut in downtown will have a negative effect on condo prices in Mira Mesa. Asianautica, you have been on Piggington long enough to read many of Bugs's postings. And he's the first one to tell you that "it's all connected".
There is a surplus of housing in the SD market. And the fact that Mira Mesa is in the "middle" (in term of prices range) does not insulate Mira Mesa from the downturn. The surplus will eventually affect all market segments.