E.g. Some gov institutions rely on old and aged software and hardware. My current driving school banned us to use anything other than IE, even though we're using newer version of Windows where Chrome can be installed, just because of the gov regulations.
Your government does not know the consequences of dead, old and no-longer-supported softwares. The dead, no-longer-supported browsers and softwares do not receive security updates and are easily invaded and hacked, as see the cases:
Let they suffer the attack of cybercriminals, then they will review their old-fashioned, retrograde and antiquated regulations.
As your school banned you, let the cybercriminals invade and destroy the school, then they will repent and review their attitudes and behaviours. If they insist on using Windows XP and refuse to adapt themselves tot the new technology, they will be erased of the market, then they will go to bankruptcy, they will see that they did bad choices in the past.
The UK government took a good attitude because it knows the consequences: businessinsider.com/why-the-uk-government-stopped…
I will explain the case of our Brazilian bank Caixa Econômica. Caixa Econômica forced us to use Flash, Java and Internet Explorer. Numberless users boycotted Caixa and migrated to other banks because other banks as Banco do Brasil and Bradesco hired programmers with ethics, the bank site did not force us to use Internet Explorer, Flash or Java, because they know not everybody owns Windows and uses Internet Explorer, for example, how can a macOS user use Caixa if Internet Explorer does not exist in macOS and Java is hated by Apple users? How can a Linux user use Internet Explorer?