Everything you said is true, although it wasn't always like this. I can remember people going nuts when Kirby Puckett's name came up in the lineup at the Metrodome and the early days of Target Field could get raucous with Mauer, Morneau, and Dozier.
Over time, the air goes out of the balloon when
1. The fans perceive the club has next to zero chance of making the playoffs, and
2. They don't recognize most of the names in the lineup on a given day.