Those appear to be well made from the limited scope we can see.
The sad thing is that louvers aren't hard to make well; not really any more difficult than holes. They are either strip stamped in a progressive die, or run on a continuous roller die. (Progressive dies are more common). Either way, it's just a matter of adjusting the shut height and adjusting a few things. Typically, poorly formed louvers are a sign of a total lack of understanding the press set-up and/or a lack of any kind of quality commitment. The only other thing that can cause louvers to not be fully formed is a severly (and I mean horribly) worn out die.
Once the perforations are made, they can then roll-form the strip into the spiral tube and cut to length.
Any company which wants to make good louvers can do so fairly easily in a high-volume manufacturing press with just a moderate amount of effort. The crappy examples we've seen time and time again really do show a total lack of concern at the manufacturing level.