Estimates and predictions that turn out to be wrong are still wrong.
And when the estimate was wrong by 50% and counting, and the ATC wasn't offering any information other than another dubious estimate, and the ATC was not handling the flights in a FIFO order, the Lufthansa pilots were left with uncomfortably little useful information about their situation.
Just a note the estimate wasn't just wrong by 50% the pilots had already been told 10min twice before, so estimate was more than 300% off by that time.
And when the estimate was wrong by 50% and counting, and the ATC wasn't offering any information other than another dubious estimate, and the ATC was not handling the flights in a FIFO order, the Lufthansa pilots were left with uncomfortably little useful information about their situation.