If the show was getting those ratings every week now it would certainly shut a lot of the naysayers up
The important thing to look at is the share. I couldnt find the figures to put in here but that is the best indication of how well a show is doing. DW could bring in 30m viewers each week, but if that's only 5% of the audience then its a terrible number. Likewise, it could bring in just 1m, but have a share of something like 75% and be considered a massive success.
The naysayers generally only take these things at face value. There was an article abotu 3 days ago that I read somewhere saying how the show was in crisis because 'it only picked up 1.7 million viewers, or something to that extent, but completely glossed over that they were quoting an iPlayer figure and it was one of the highest ever figures on the platform. Another article this week, on DS I think, was mentioning how AGMGTW was a failure with only 5.5m when Tennants last Christmas special got 10m and so the show has managed to lose half its viewers, when again what they failed to mention was that they were comparing an overnight in the summer to an official from Christmas Day of all days.
So yea, rant aside, the figures are never quite what they seem, but some would rather not look deeper. I'd imagine that at the time, these would have been pretty good by any standards