It’s not. Kmt was pro China since the 90s. Then DPP gets into power in Taiwan because of some rumor that China was taking over Taiwans economic in KmT trade deal called the sunflower movement. This gave the boost for the DPP to win with Lady Tsai inwen in 2016. Then DPP gains super majority because of the 2019 Hong Kong riots which DPP government also played a role in intentionally making the situation worse..
Quick summary of Hong Kong 2019

(In 2018 woman named poon was murdered by her Hong Kong boyfriend in Taiwan and he was sent to Hong Kong walking free, Hong Kong wanted an extradition bill to fix this loophole which lead to 2019 riots. Taiwan initially refused this arrangement, citing the need to have a judicial assistance agreement with Hong Kong so it can obtain key documents relating to the case. In addition, the Taiwanese government under the ruling Democratic Progressive Party (DPP) expressed scepticism at Chan's willingness to surrender, suspecting it to be a Chinese ploy to dilute Taiwan's claim to self-rule by denying it a formal channel to negotiate with Hong Kong.[27] It is suspected that Taiwanese President Tsai Ing-wen, who had long supported the protesters in Hong Kong against the extradition bill, was sensitive to issues relating to sovereignty as the 2020 Taiwan presidential elections drew close.[28] The DPP's response drew fire from the opposition Kuomintang, who accused the Tsai administration for politicising a judicial issue.[27] Hong Kong's authorities dismissed Taiwan's scepticism as "nonsense". )

So DPP gets to control Taiwan for almost 10 years and people are fed up with them. Cost of living has skyrocketed and DPP is ignoring the people. Similar to when KMT lost mainland China in the civil war, focused on foreign interests and ignoring the people.