Of course that's also why every second Batman story is nonsense. No Man's Land? The JLA should have fixed most of the problems in a weekend. Knightfall? Call Zatanna, have her mend that broken spine, and have Superman and Flash help round up those escaped prisoners. Batman RIP? Tim should have called in the Teen Titans at the very least when things went south.
Devin Grayson's not the only one that ignores the shared universe when writing Batman books. Because honestly, you'd go nuts trying to write Batman family stories if you had to keep going "but couldn't they just call all their Superfriends?"