I also subscribe to the true love theory. Magic in this world has to have a catch. It has to have specific rules. It has to have limitations. Especially given the fact that this isn’t any ordinary type of magic. This is the magic of true love. It’s users must posses certain characteristics in order to use it. We’ve already seen evidence of this. Rumpel could only make the true love potion when Snow and Charming were in love. He needed their love in order to make the potion. So the users or “test subjects” need to be in love in order to create the magic of true love. That is the key ingrediant.
The same goes for true love’s kiss. The magic can only work unless the two lovers are truly in love. We’ve seen this numerous times with Snow and Charming, Belle and Rumpel, Emma and Henry, and the creation of the true love potion. You can’t just use the magic of true love, or create the magic of true love if its users are not truly in love. That will be the catch.