Workshops don’t want to raise old tires – Reifenmafia?

In my basement I had stored tires for a long time, which are 20 years old in the meantime, but hardly ran off and have no cracks or the like. I wanted to have them raised now – the workshop refuses however. The “tire specialist” explains quite furiously, it is forbidden to drive such old tires, so one would not get a HU badge and would risk a parking ticket. And the tires could “rupt” already when inflating, or on the highway etc. He as a workshop is in the liability. Isn’t it true – demand from experts (DEKRA, ADAC) shows that there is no limitation of the age of tyres (except trailers). And that tires have a steel belt for a long time, which makes it difficult to “place” should also be known 😉 And the liability for such work has basically the holder – at least if he brought the tyres or other parts himself. So what is the reason for such behavior? One should think that the workshops at this And other workshops do the same. Apparently there’s a real deal – and they think they’re better at driving if you fool the customers – by selling more new tyres? Who has had similar experiences? What can you do about this “maferia”?