[adrian_b]

One can choose to classify the chemical elements with whatever words one pleases.

Nevertheless, some classifications are much more useful than others.

A classification that no longer uses the traditional distinction between metals and semi-metals is much less useful than a classification that distinguishes these 2 categories. Neglecting this distinction demonstrates a lack of understanding about which are the properties that determine the usefulness for practical applications of the chemical substances and a lack of understanding of how such properties vary with the atomic number.

Moreover, after one chooses some classification rules, those must be followed consistently. For example, anyone who chooses to call bismuth as a "metal" must also call carbon as a "metal", because the most stable state of carbon in normal conditions, i.e. graphite, has exactly as much reasons to be named as a "metal" or as a "post-transition metal" as bismuth has. There are a very large number of chemical compounds that are semi-metals, but among the pure elements carbon, antimony and bismuth are semi-metals (while boron, silicon, germanium, selenium and tellurium are semiconductors).

The reality is that too many authors of manuals just copy and paste automatically texts from other works without stopping to think whether they are correct and consistent.