Because a poll asking a direct question is a hell of a lot more accurate in gauging how the population feels about the issue.
Political parties can lose elections for their stances/actions outside their main one – which seems to have been the case per the actual person from Taiwan that responded to your comment. It doesn’t matter what a party is called or what their main goals are if they’re bad at their job.
If and when the people of Taiwan decide they want reunification, it will happen. Thankfully Beijing isn’t going to be allowed to force the issue.
You want polls, how about this poll conducted by a Taiwanese university where the majority of Taiwanese want neither reunification nor independence, but the status quo? The majority of Taiwanese people wanting the status quo lines up with how the pro-independence party ate shit while the pro-status quo party made huge gains. The DPP got BTFO so hard the current DPP president Tsai Ing-wen had to resign as party head.
The majority of Taiwanese people has always wanted to remain status quo, as indicated by the two triangle data lines in the plot. Since declaring independence is basically asking China to attack and that peaceful reunification is not desirable (for >90% of the population) either, the majority are of course pro-status quo. It does not line up with how DPP ate shit last year.
peaceful reunification is not desirable (for >90% of the population)
Again, this was “forced” reunification in that poll, i.e. military takeover. Of course people oppose that. I think at least the plurality opinion is against peaceful reunification under the PRC too, but it’s not by as high a margin.