Because the magazines suck.
There are flaws with the Hi-Point, though probably no more than any other pistol.
Mine (C-9) ran well for about 200 rounds, and then the feed problems started. I know my way around this style of pistol, could only conclude it was the mag.
Disassembly is horrible, you need a punch and hammer.
Beyond that, it's a durable little gun, and as others have noted, serves a purpose until you can step up to something a little more refined.