The problem is that the presence of the Tefal brand used to be a sign of quality. Now you've got both decent products and garbage being sold under the same brand, with only the price as a quality indicator.

This dilutes the brand, and it is only a matter of time before the reputation of the cheap items will be seen as the standard for Tefal, which leads to the sales of their expensive items dropping, which leads to them trying to bring that back by lowering their price via lowering their quality. Congratulations: Tefal is now a brand where you can choose between cheap garbage and overpriced garbage!

Next steps: they shut down the European factories, struggle to compete on the budget market, and finally kill the business and sell the brand to a Chinese company interested in milking some cash out of what remains of its reputation.