You said "a bursting of the bubble," and then asked why people aren't considering a decline. I think most people accept that investors are getting pickier, but

You said "a bursting of the bubble," and then asked why people aren't considering a decline. I think most people accept that investors are getting pickier, but that's not the same as your first paragraph (the sole contents of the original comment) suggesting a bubble burst, which by definition is a violent event.