Mind you, I'm personally opposed to a sugar tax myself, since I like soda, so you have my bias explicitly stated here. I'm also interpreting his initial thing as a proxy for the more established "unhealthy food tax", most commonly proposed as a sugar tax.
>It’s not about “virtue points.” Its about understanding the true nature of the problem. Poorer people don’t disproportionately eat that food just because they’re too dumb to know better or somehow lack willpower. They often lack the time or access to higher quality affordable food. So by taxing it, you’ve just made a hard lifestyle even harder. To a large extent, the food consumption is the symptom of much larger problems. It’s not like just taxing soda will fix the US’s obesity epidemic. (The percentage of calories coming from soda doesn’t actually amount to enough - the numbers I’ve heard are around 6%). If anything, this type of taxation is the feel-good regulation that ignores the root problem. IMO that’s anything but pragmatic and tends to be be a shortfall of technocrats who sometimes fail to see the larger picture that spans multiple domains.
So, this isn't a feel-good regulation, nor is it something that ignores the root problems, The current research shows that a sugar tax would be effective. The fundamental issue here is that they ingest too many calories, and sugar is by far and large the easiest way to do so. You're saying that they'll have problems affording sugary foods. That's the entire point. This is not a tax that's targeted at revenue or fairness, this is a tax that's fundamentally constructed to modify behavior.
Furthermore, from a nutritional standpoint, 6% of calories from soda is huge. That's a half litre of soda per day or double what the Europeans drink on average. Remember that for obesity, it's the little things done many times that gets you. A consistent increase in calories per day, compounded over the years is exactly how you get an obesity problem. Of course it's one of many factors, but it is an important factor and low hanging fruit at that.