IMO the laundry thing is an easy example of the larger issue of extreme privilege. Being able to live on a rich friend’s property in the woods by a pond sounds awesome. I’m sure I would love that and it would do amazing things for my well-being. But that’s just not a relatable thing for most people and it can really sour the message.
I actually think your hypothetical smoker is a great example of the opposite. Someone who lived it, understands the struggle, and ultimately regrets their choices is exactly who you want to hear from. It’s why the really cheesy don’t smoke PSAs don’t ring a chord with most people, they don’t feel genuine.
I don’t think Thoreau is some enormous hypocrite, but I do absolutely understand why some people might feel bitter about it when they learn the greater context.