I understand where you are coming from and seems quite logical to me, from a customer perspective.
But I think that domainers have rebelled so much in the domain parking space, that right at this point most parking companies are giving all they really can. This is of course looking at things from my end, but I could be wrong.
The real decline in revenue I think has been with the clean up of the major search networks that syndicate the advertisements.
I can name 4 things from the top of my head that resulted in big declines over last 2 years:
1. The recent Yahoo TQ system adjustment
2. Ban of MFA sites on Google/Yahoo which were drastically driving up advertiser CPCs and competition.
3. Ban of arbitrage on Google which was drastically driving up advertiser CPCs.
4. Ban of the Ask agreement, Lycos agreement, and InfoSpace agreement that no longer allows them to syndicate to domain parking companies. (Companies affected by this were: Bodis, ParkingPanel, Parked, Skenzo, HitFarm, and many others).
I hate to say this, but there are many more to come, I know at least two that I would not be able to discuss, but they are definitely coming.
At this point, only the parking companies can really help increase revenues with better technology.