'Hal ini demikian kerana' is wrong grammatically

I will start this year's first post with the expression 'Hal ini demikian kerana'. It has been deemed correct to translate 'It is because' until Tatabahasa Dewan, third edition included 'adverba' or adverb as one of the Kata Tugas (Functional words).

As an adverb, 'demikian' cannot act as a predicate. As such, 'hal ini demikian' is grammatically wrong. If 'hal ini' is followed by 'berlaku' to form 'hal ini berlaku', then it is correct because 'berlaku' can function as the predicate of 'hal ini'.

With the explanation above, 'Hal ini demikian' should be changed to 'Hal ini berlaku demikian' or 'Hal ini dikatakan demikian'. I will explain why this grammatically correct. An adverb modies a verb. In this case, 'demikian' modifies the verb 'berlaku' and 'dikatakan'.

Now let me make two sentences one of which has he old expression 'Hal ini demikian keran' and do the necessary change to make it correct grammatically.

1 Pelajar miskin itu tidak mempunyai uniform sekolah. Hal ini demikian kerana keluarganya tidak mampu membelinya. [The poor student has no school uniform. This is becaue his family cannot afford to buy it.] [Hal ini demikan kerana is wrongly used here]

2 Pelajar miskin itu tidak mempunyai uniform sekolah. Hal ini dikatakan demikian kerana keluarganya tidak mampu membelinya. [The poor student has no school uniform. This is becaue his family cannot afford to buy it.]