The word "beta" does seem to get jumped on quickly by those defending poor performance. Here's a quote from the crash in 2016:
"It is important to note that Tesla disables Autopilot by default and requires explicit acknowledgement that the system is new technology and still in a public beta phase before it can be enabled."
A Tragic Loss
Yes, I believe that leaving something in beta allows this kind of legal defense, or at least encourages a blame the victim mentality. Are they leaving things in beta on purpose for this reason? Well that would be unethical, so of course not. Yes, surely it must be "abandonware" as S4WRXTTCS points out. They must have just forgotten to finish it.