The problem with two one inch goldfish (if they are common goldfish) is that they have the potential to reach at least a foot in size if provided with adequate space. I believe I read on a goldfish forum that a goldfish can attain its full adult size in around a year if housed and cared for properly.
Even fancy strains can grow to the size of a baseball, if not more.
What is happening to your goldfish now is that they are being stunted. Stunting can severely impact on the longevity and health of your goldfish, even if they don't show it. I had a goldfish that used to live in a 10 gallon tank and is at least 5-6 years old. It is now in better accommodations, but is only half the size it should be at this age. While it still looks impressive to visitors, I know that it has been possibly permanently stunted by its previous life in that tank.
I wish goldfish were not so easily obtainable, as their care requirements often go beyond what the average person can provide. And when you think that they can live for around 15-20 years, you can see that they are often much more of a long-term investment than most fish.
The problem with this thread is he has been on these forums for a long time now, and really should have known better than to do it.