You need to gain honor to get experience.

Obviously winning the match is the best honor.
But even if you lose, any honor (from objectives) that was earnt was experience points as well.

If you play in a WSG game, and lose 3 flags to 0 flags...
Even if you farm them a lot in the middle and have say 500 honor kills...
Unless WSG is the bonus honor battleground (in which case you get bonus honor for losing, but a larger bonus for winning), you would get zero honor from objectives which means no experience for that battleground.
If you were able to return one flag, you would earn experience for that.

Something like Arathi Basin might be better.
If you were to hold two of the five bases...
You would lose, but you'd get a 1600 to 1000 (or whatever) score and that would translate into experience.