They are challenging to keep, require a large tank (much larger than the one this animal is being housed in), are aggressive, require extreme care when doing water changes...
Even the smallest of 'em require a minimum of around 200 gallons, last I checked: there may be some other species i'm not aware of, of course.
There's really only so many ways for one to say "don't do it" honestly
While sharks are beautiful, there are very few folks who have the space to keep a tank large enough to properly maintain one. I mean jeez, this thing (if I'm not mistaken) is a black tip - those are not even a particularly small breed of shark!!! Anything under 1000 gallons is way, way, WAY too small for this guy.