Is there something inherently appealing about songs in languages you don’t understand

What do you mean here? That you don’t understand french or that we don’t understand english?
Just curious.

Look for CDs by Les Baronets, Les Gants Blancs and other Quebecois bands from the 60s and 70s. They do the translations well, had hits at the time, and is what les Justiciers are referencing.

"mauvais gars, mauvais gars, kessé tu vas faire, kessé tu vas faire quand ils vont venir pour toé..."

However, I'm pretty sure there's a difference between this case of les Justiciers/French Quebec people (like me) with songs in english, which is a language most of us are at least a bit familiar with, compared to real languages we don't understand (in my case, must more every other languages out there) or even, not understandable by design. Some bands/artists have built imaginary languages for their music. In that case, without being able to understand the lyrics, we have to put them with the music, and I'm pretty sure it means we don't use the same part of our brain to process this music.

In any case, this "compilation" is definitely not made to be "good" music in French. They translated the songs with the obvious intent to make it funny, and probably to make them bad too (it's pretty improper (écrapou) french). There have been more or less successful cases of translated songs between French-English that had decent success, though generally, this comes with different lyrics, and the subject of the song might change a lot.

Often, lyrics are chosen with a musical intent to create something, and fit with the music (or vice versa). Thus, straight translation will most likely not keep the same sound/rhythm as the original track. Also, there is much that cannot be rightly translated word-for-word or babelfish-like, like it's been done here, while keeping intact the original lyrics' meaning.