Probably the wording in the article that seems to say exactly that?

The Singapore Government’s Factually website states that all goods brought into Singapore are subject to goods and services tax, currently pegged at 9 per cent. However, travellers are granted GST import relief based on the duration of their trip.

Those who have been overseas for 48 hours or more are entitled to GST relief of up to $500. For trips under 48 hours, the value is capped at $100. The GST rate is currently pegged at 9 per cent.

These amounts apply to the total value of goods bought overseas, excluding liquor and tobacco. Any value above the relief limit is taxable, and travellers are required to declare it upon or prior to arrival.

Singapore work permit, employment pass, student pass, dependent pass or long-term pass holders, as well as crew, are not entitled to GST import relief.

The term goods isn't specified, but could easily be interpreted to mean absolutely anything they want potentially.

I read the article.