After all they work with fairy tales, and while I doubt that true love is a concept they put much merit into, I am quite sure they are aware a lot of people and particular many in the audience do, not just has some idea but as an ideal of how good romance should be. Putting so many true love ideal couples into one place makes it easily look as something casual, nothing special. Funny enough I would be the first to agree, true love is not special in the sense of something only a few could find, but I maybe OUaT has an inflation problem. True love is something that looks kinda cheap to come by by now.
One of my biggest issues with regards to true love on ONCE (or even just romance in general, if TL has not yet been proven) is ignoring the past and this works for every single couple to varying degrees. Now, again, I’m working with canon text…nothing the shippers have interpreted for themselves (please bear this in mind)
Snowing: when did Snow learn that David was hiding his identity; that he was not James, the Prince, but David, the farmer? Was she not alarmed by this? Ladies and gents, wouldn’t YOU be alarmed by this?
Rumbelle: Everything Rumple’s ever done from the murder of the maid to Milah to the Curse itself, that Belle either doesn’t know about OR knows about but is “ok” with and instead of it tainting her own perception or even her personality, leaves her as the sweetheart (to quote @Myril).
SwanFire: Neal’s past as Bealfire and where he came from and his whole life story.
OutlawQueen: Much like Rumbelle, everything Regina has ever done including persuading another man to kill her husband. Robin has “head of” these things Regina has done but would you honestly want your 3 yr old around this kind of person? Would you not hesitate for a very long time before trying a relationship?
CaptainSwan: Hook’s own pirate laced past, that includes the most recent lost year, that either Emma doesn’t know about or knows about and doesn’t care about, both being equally problematic.
The big question: do your partner’s past not matter at all? Especially one that is built on deception and blood? It’s all washed away because “it’s true love/soul mate/a second chance/ fate.” Is THAT the kind of message that we want to uphold?