It wasn't really the B lineup today, just a day off for Beltran (who needed on, last night notwithstanding).
I'm pulling this directly from my ass, but they just don't seem to gear up for day games. They may get a run or two early, then they try to coast for the remainder.
You could see that outcome coming even before Alvarez hit the dinger that gave them the 3-2 lead; the Cards were either gonna win that game 2-1, or they were gonna lose it.
If you can't draw a crowd, draw dicks on the wall.