I think the author suggests that chemical-psychological research is quite inefficient, given that so many discoveries were random discoveries rather than products of systematic search and invention.

The point is that chemists are tasting a lot of the novel stuff they synthesize, if it doesn't look like it's going to cause instant cancer, even they they aren't supposed to.

Watching NileRed regularly, it does not at all surprise me.

I don't think there's some huge point beyond exploring an interesting question, and raising it in a forum where it's possible some people with more specific domain knowledge might offer some insight.

I don't think it's meant to imply a conspiracy, rather that lab safety around novel compounds is probably not as tight as people assume it is.

I will put forth another (possible) explanation: fake sugar has to be widely marketed, and "we were doing Important Science when we accidentally discovered this fake sugar" is a more marketable, easy-to-understand story than "we added/removed groups on a range of compounds determined likely to be sweet based on a literature review, in order of how amenable the reactions are to mass production, then tested each of them in rats".