If you have a billion in stock but live a humble life, what's the point in taxing it? You'll live the same way, and sell some stock. But selling stock to pay taxes is not necessarily good, unless whatever the government does with the money is better than whatever the company was going to do. Sure, it could be good, but it's not a slam dunk.
The idea of wealth is just very different in the modern world. If wealthy people were hoarding (keeping a bunch of stuff without using it), then taxing would put that stuff back to use. But wealthy people hold onto money-producing assets, which means someone is still using the stuff. Not always, but often. So it means that taxing it just takes it from one use (say, by a corporation) and puts it to another use (maybe a government use).
I'd much prefer that we tax consumption. It could be a 1000% tax for a Ferrari. Encourages better use of stuff and can be very progressive without triggering as much anger.