LT is not a learner’s tool exactly. But you do have a point. Nevertheless, there are far too many situations to translate from any language to any other.
An intermediate alternative might be to translate all of them to a generally known language, e.g. English.
But to be honest, I would consider translating all Dutch rule’s messages to English too much work as well.
It is not so strange to expect some knowledge of the language you are writing in.
And unfortunately, automatic translation is far from reliable still.
Don’t forget, this is not a large software company with millions to invest; it is a community, working for free (mostly).