This might be true for YOUR use case and company. We are talking about Greek high-schools, which use like 1% of the capabilities of Excel,Word or even LibreOffice's calc and writer. So IMHO this point is moot.
If nothing else I would prefer Greek students get used to the emphasis writer places on using styles instead of "ad-hoc" formatting.
LibreOffice is not Apache Licensed or driven by Apache. It is a fork lead by "The Document Foundation". You can read http://www.documentfoundation.org/.
If nothing else I would prefer Greek students get used to the emphasis writer places on using styles instead of "ad-hoc" formatting.