Certainly the real critics (I'm thinking of the "HS2▸ is an extravagance as it's just shaving 15 minutes off the London-Birmingham time" brigade) will not be impressed by a one-off publicity exercise when there is still much to criticise.
You are correct - but then those who are principled anti will always look for things to criticise ... and it is not an [either/or] between one of publicity and getting the base system right - both can and should be done in parallel.