When almost every study shows one thing and a small minority shows another, it's probably best to approach the latter with some skepticism. Not that the premise is wrong for sure, but the data doesn't really support it, I'm pretty sure.
In the particular case of MSG (excluding allergic reactions to it), for instance: there certainly isn't data to support banning or regulating it, so the only question left is... should you (the individual) try to limit it? Eh... maybe. Experiment with it and if you find it helps, sure, go for it. But it seems unlikely to be something that would be a big help. For many small dietary changes (likely including this one), it feels sometimes to me that people make them to avoid the serious, underlying issues of "eat less sodium/sugar/saturated fat than you probably currently do, eat less in general, eat more of the things your body actually needs, exercise more" which I see the article even retreats to at the end.
On the specific topic of sugar, it's... bad, but not directly bad, if that makes sense? Debating whether it is a "toxin" (wtf does that word even mean) is pointless. It's unhealthy mostly because you can eat a lot of it very easily without sating your appetite and thus get way more calories than is healthy. This isn't really news and to some extent I feel trying to debate just "how responsible" it is for obesity or diabetes doesn't accomplish much. As individuals we all know it is something we should try to eat in moderation (or if we don't know this then we need more education so that people do... I'd actually be interested in a study about that). As a state, eh. That depends on your politics somewhat. There is probably enough evidence to merit consideration for the idea of taxing/regulating it in some way (assuming one is open to this idea in general), but we would have to be very careful that any policy doesn't have unexpected consequences, so I am somewhat leery about this.
