Honestly, Batman does not take himself so serious or have such a frail ego thst he wouldn't do this if it was practical. He lacks Wolverine's healing factor and adamantium skeleton that makes the move a practical choice. Whenever JLA needs to get somewhere fast and the Batplane is not a practical option, he's carried like a child in the arms of Superman, Wonder Woman, or Flash. I seem to him riding piggy back on Flash at least once. The only times he gets to ride around with more dignity is when one of the Green Lanterns transports him in a bubble. Although, I think he still prefers to be carried by Wonder Woman even then.