Sure, but he point stands: failures of nattow AI systems aren't informative about likely faulures of superintelligent AGIs.
They are informative, but not because narrow AI systems are comparable to superintelligent AGIs. It's because the developers, researchers, promoters, and funders of narrow AI systems are comparable to those of putative superintelligent AGIs. The details of Tay's technology aren't the most interesting thing here, but rather the group that manages it and the group(s) that will likely be involved in AGI development.
http://www.wired.com/2016/03/fault-microsofts-teen-ai-turned-jerk/
Could this be a lesson for future AIs? The AI control problem?
[future AIs may be shutdown, and matyred..]