CHLOE Excuse me, what are you talking about? I think you didn't understand the real purpose of this program.
It wasn't intended to be used as a video-joining tool, nor does it even come close to that (since you mentioned VisualHub and D-Vision, which are video-related apps). Instead, it was specifically meant to be used to join/concatenate smaller pieces of files which have the extensions .001, .002, .003, .004 and so on) and output a single, larger file (this is explicitly stated in the AJoiner's description here at Macupdate).
These files can be in any format, as long as they use Mastersplitter's naming convention (.001 - .999)
Giving this program such a low rating when you obviously didn't have a proper understanding of its purpose just seems unfair, IMHO.