what about the fact that you cant use it in Stadium, it doesent even show up! that another point for the creepy factor, or how about the fact that it becomes a Ditto when used on Stadium 2? that opens up quite a few questions
Combination of workarounds due to hardware constraints and oversight on the developers part. Missingno isn't part of some sort of global conspiracy, it's just developers doing what developers usually do: be lazy (GAAAAAABE). As for stadium 2, the developers probably put in the defaulting to Ditto so you wouldn't mes sup your game cart.
As a developer myself (small software company), I can attest that we are not all perfect and have to make decisions based on project constraints, deadlines, and nagging clients. I don't know how it exactly works for video games, but from what my more experienced colleagues tell me this is true for all software projects.