When someone says "RL takes precedence," what they really mean is that you're not important. To them, you're just a doll that they take down from the shelf to play with when they feel like it, then they put you back up on the shelf when they're done.
Of course, they don't like it when you treat them the same way, because, well, *they* are important.
But that's just the way things are. *We* and *ours* are important to ourselves. And everybody else is chopped liver. And we assign greater value to things that are tangible, or at least things that *seem* tangible to us. Except it's too arrogant to admit that, so people just say, "RL takes precedence."
I've never said "RL takes precedence." But if the occasion arises, I hope that I'd be courageously honest enough to say, "I'm sorry, you're not that important to me. Cutting my toenails in RL takes precedence over you in SL."