According to your quote and linked web site, those Indian passport holders also have to "possess a valid visa or permanent residence certificate issued by U.S.A., Canada, Japan, U.K., Schengen Convention countries, Australia or New Zealand" to be eligible for not needing a visa to enter Taiwan.
Exactly. That's why I said Indian passport holders were "eligible", and provided the link and complete quote from the Bureau of Consular Affairs in Taiwan.