Most people are familiar with income tax, because they know that money is removed from their paycheck every month. Many also file tax returns.
A wealth tax, where a fraction of your bank balance is removed every month, is a totally alien concept to most people. If you haven't thought about it before, it can take a minute or two to wrap your head around what it would actually mean.
In a survey context, all of these questions can be answered on autopilot by mistaking "wealth tax for rich people" with "higher taxes for rich people," which are definitely not the same thing.
Whether or not you think a wealth tax is a good idea, I don't think we should let politicians sneak this through unless we're confident that the public actually understands what is being proposed. As other comments mentioned, income taxes started out as "wealthy only" and have since trickled down to the working poor.
I don't think most Americans want a tax on their bank balance.
Edit: No, I'm not arguing that people are dumb, just that they tend to rush through surveys. When rushing, I think this would be an easy mistake to make.