You think the number of users filling in the ratings are significantly affected by the quality of service, in the same way as forum comments are? Bearing in mind that it seems quite a small proportion of Main Site users are forum users so most are not geeky.
As for you gaining customers on Entanet, you and Aquiss I expect are the only significant ones.
You also have cause and effect. If overall numbers have fallen the complaint rate from the remainder, assuming no capacity reduction, will fall for at least two possible reasons. Fewer on the same capacity so better performance; and the remaining ones will by definition be more tolerant or less demanding.
The result of course of fewer problems is hopefully the observed increase in new signups due to the higher satisfaction levels of the existing customers.