I think valuing the self is important. But it is not more important than valuing others.
I think treating ourselves well is important, but not more important than treating others well.
I think that practicing kindness and basic courtesies toward oneself and others are all equally important. If you feel tired or low or whatever, and your child asks for a hug or for dinner, do you treat him or her with kindness or courtesy? If a stranger passes and says hello, do you respond with courtesy and meet their eyes with respect? And so forth. Or do you skip all this because today you are not tip-top? And treat them unkindly, or with cruelty or apathy? Perhaps with violence, for some?
I don't think that telling everyone to seek their happiness will result in authentic love of self across the board. Many currently understand "seeking their happiness" as self-indulgence and gratification of all wants and desires, very often by means of using others, even harming or killing them.
Manners, courtesy, simple kindness and acknowledgement of others...these are very important indeed and they are manifest acts of lovingkindness. If we feel we are overextending ourselves in a relationship, we may need to back off a bit. But that doesn't mean the kindness in action that we extend isn't real just because we don't "feel" it in the emotional sense. Not everyone is as emotional as others, and yet they may still find great joy and peace in day-to-day exchanges and relationships of all sorts.
If we are deceiving others, that's another thing altogether. If we are not authentically present and engaged, then that too is another thing altogether.
But humanity is a collective and we cannot attain the fullness of our humanity without community. We cannot survive infancy without touch, and our brains will fail to develop many higher brain functions if we are not raised in loving community with others. The same applies regarding our emotional and spiritual development...these ripen in relationship with others, within our circle of belonging in which we interact. Thus I cannot fully know and care for what is ultimately right and true and good for me, unless I also know and care for what is ultimately right and true and good for you and all others. And all that is.
Otherwise, if I seek and care for only my own wants and call that "my highest good", I may do great harm to self and certainly to others. And same for them, toward me. In the context of what is the highest good for you and others (according to you, and according to others), then I can seek my own highest good from a place of equanimity and authentic love for all.
Peace & blessings
7L