My impression is that he is against working in general. I do not think he would see any occupation in which a person is chained down to others, or chained down to their own greedy desires as being "noble" he is brutally critical of the wealthy and merchants as well.
He believes in completely free and independent living in which a person lives purely for themselves. Because he also says that he would not advise anyone else to live the way he lives either, because he thinks each person needs to individually choose their own way, and so he would not want to be the means of another choosing to live in a way that is not born purely from their own desire and choice.
He starts out with the example of manual labor, but I do not it as simply an attack upon labor, because by the end of the chapter her pretty much tears down every institution and occupation of the civilized world. He sees it all as being interconnected and all of it as a way of keeping people as slaves and preventing them from truly thinking for themselves of behind independent individuals.
But rather as being trapped in this cycle in which they feel as if they have to work in order to by the stuff they are led to believe that they need.
For example in the case of the cabinet maker, while I don't know if Thoreau would "approve" of the trade, as well he seems to be generally against trade in general and those concerned with making a profit, but I tend to think he would have more respect for the craftsman who made furniture because it is what gave him pleasure in life, then he would for the more industrialized labourer who saw only the profit and worked himself to death in work that was meaningless to him.

