In all the customer service training that I've received down the years, you are always thought that a complaint is like gold. You can choose to either act on or ignore a complaint. However, ignoring a complaint tends to lead to people not parting with their cash for your product/service down the road.
MM in not publicly acknowledging the issues with the Supertrain Mk2s is damaging their own reputation.
Even, Bachmann have come out and acknowledged issues with their models in the past, and if I remember correctly, have even gone so far as to recall models that were not up to scratch and send them back to China. Reference to this can be found over on RMWEB.
MM can either acknowledge that an issue exists and publicly announce measures they will take to deal with the issue, or be left with a large stock of unsold Supertrain Mk2's.