The two premises of this article are that local languages are in some sense valuable and should therefore be preserved.
To question the first premise - valuable to whom? As the author herself admits, there are both students and teachers who regard local languages as an unnecessary distraction. If education is to be regarded as instrumental for later economic activity, then it is hard to argue that local languages are of greater import to a student's future than mathematics, the sciences and the two predominant languages Chinese and English. Perhaps, on the other hand, there are some students who would like to learn these languages for their own sake but are discouraged from doing so due to the demands of compulsory State education.
That brings us to the second premise - how should the preservation of local languages be attempted? The author's answer is to use institutional power in two ways: first, at the "macro" level in the implementation of nationwide language policies, and second, at the "micro" level in the transfer of greater power to local teachers to implement their own local language policies. Yet contrary to the author's leader statement for this article...
"A bottom-up approach to language learning and acquisition is necessary to halt the decline of local languages in Taiwan."
... both of these ways are in fact top-down approaches in which policies must be designed for the "encouragement", if not explicit coercion, of students into using local languages. A truly "bottom up" approach would presuppose that students are the ones making decisions about whether and which local languages they want to learn, but that requires freedom of choice which is something students do not enjoy in compulsory State education.
Homeschooling, unsupervised by the State, and supplemented by parents hiring independent local language teachers might offer a way in which students could gain that freedom of choice - not just for the learning of local languages, but for the development of their natural interests in other subject areas too.