A reminder of several things:
1) The goddess of love, according to her own followers, is a goddess of lust, not love. Actual love is about giving of yourself for the betterment of someone else. Real love would be more modest and earnest and less superficial.
2) The king is not a good king. He's got high taxes and wastes the money for vain reasons.
3) Jinguji is the most selfish person in this manga.
Yeah, Tachibana isn't mature, but he didn't intentionally sabotage his best friends chances of getting a girl because he doesn't want to spend less time with him while justifying it by projecting his own (incorrect) absolute cynicism onto every woman his best friend might be interested in.
It's genuinely refreshing to see characters with flaws like this and an execution that realistically hashes out the issues these flaws tend to generate. This is a positive point for the manga, even if it means Jinguji needs to learn to move forward with life.