The amount of programmes run are often very few but they have to work. Therefore it has to be secured against intrusion or crashes. Demands here are high. There is usually an incentive for people to force the system. If data is intercepted by outsiders there is a chance that no backup will help.
Educational systems are examples of the opposite.
Schools have to look forward, encourage creativity and the hunger to try different solutions to a problem. This takes a lot of different programmes and hardware settings and sometimes crazy solutions. And to make it worse many of the users do not understand what borders are unsafe to cross or might even want to test such borders. But at the same time loss of data is not the worst threat. If something happens to the system it can always be backed up.