Courtly love is seen from a slightly skeptical angle in Romeo and Juliet.
The practice is associated with Medieval European upper class couples. if you look at middle English poetry there are some wonderful romps in the genre, full of knights and damsels in distress.
Romeo and Juliet fit into the category of "courtly lovers" because there love is not allowed by the social, (in their case specifically familial,) world they live in; Romeo woos Juliet at her balcony with sonnet verse, a form widely used in courtly love scenarios, (see Petrach); and they have to go through considerable adversity to be together.
However, and here's the rub, their romance is not merely tragic, it has farcical moments that completely undermine their initial impact - which is beautiful, utopian, true love.
On the one hand there's Romeo's fickle nature, highlighted by his quick jump in affections from Rosaline to Juliet.
And then there's the near misses, the letter that just misses its recipient, Juliet waking moments after Romeo dies, it's all good tragic stuff, but it's also just a little bit pantomime.
So Shakespeare presents it as, in theory, a wonderful concept full of genuine, innocent, feud healing love - but the way their plot unravels hints at a raised eyebrow from the Bard.
It is, after all, a highly contrived, exclusively upper class way to romance, and it wouldn't be Shakespeare if he'd portrayed it in an entirely favorable light.