Plus, manufacturing is a great way to get jobs in your city if you're in a bind and cannot successfully manipulate commercial's demand in your favor. It probably won't provide jobs for high-wealth residents, but it can definitely fulfill jobs for low and medium wealth residents. Manufacturing requires very little to move in and has decent benefit. Dirty industry, on the other hand, should definitely be taxed high in my opinion and their development should be discouraged. Too much pollution (air and water) and too little benefit.
Actually I have seen some high wealth residents go work at manufacturing industries. But I cannot remember them going to work at the high tech industries.
High wealth residents prefer to work in commercial buildings.
So I think having manufacturing industries is important to at least provide the choosy high wealth residents with jobs. They are very difficult to keep employed.