People of a certain religious bent believe that 'persecution' (which usually means the same thing to them as it does to SJWs, which is the mere fact that people don't agree with them) is a holy state. Christianity has a long, proud tradition of getting boners for martyrdom and persecution, so his parents are probably so proud because they think he's being SUCH a good Christian by virtue of the fact that people hate his message and thus he is being 'persecuted'.
There's a quote somewhere (probably several) about how the 'true Christians' are the ones who are persecuted and 'blessed be the persecuted', which is clearly a throwback to the early days of Christianity when they provided a steady diet to Roman lions. This doesn't happen anymore in most of the world, but Christians still want to feel all persecuted against so they can feel so holy and maybe even be martyred, which probably means getting yelled at online or some crap and not thrown to lions or set on fire. They wanna be all holy and persecuted, not UNCOMFORTABLE! Geez!
Christians like this asshat are never comfortable with just their own business. They have to make sure everyone everywhere plays by their rules, because misery loves company. The seven deadly sins are really just very natural, normal human impulses... it's basically just setting you up to fail, setting you up to NOT be able to live up to god's (and your church's) expectations of you, forcing you to live in a perpetual state of guilt and shame over things you can't control, leaving you feeling like you 'need' this church/religion which is what's telling you you're crap to begin with. It's a classic abuser technique.
Also, lots of religions are really ill at ease with happiness. Basically, if it's fun and feels good, it's a sin.