Because it was based on the Debbo source which was visual basic wich was based on another source but at the time the developers of the projects didn't know the same of the program languange as they do now. They were praised because they could build an server at that time since there weren't really that much sources to learn from.
Bloodline came way after the first emulators of the old school emulators, it was merely an edit of Debbo with a lot of changes.. A lot of the original code wasn't even changed.

