You did not mention midsized divers like the caliber 6458, nor the 7c43s. There were a few odd midsized lady divers too...in such small batches that most of us did not notice them. I had found one once, a 'Brazilian or Irish green dial' and sold it to a fellow in Europe!
In fact here is a magenta ? colored version I found on the Yahoo auctions recently and had to bookmark it!
pianoman10x-img600x450-1416747442kn0umv32419 by
blingmeister, on Flickr
And here is a sample of the midsized quartz 6458s which were produced in a short run of 2 years? They came in 4 colors: black, orange, white and a teal blue dial...
seiko 6458 Lamborghini orange by
blingmeister, on Flickr
I guess it is only natural that your collection reflects what you have learned from Seiko forums and what collectors have posted of their divers (in this case your stated interest). It is normal for Seiko to continue a model for about 8 years and then it creates new models. They usually keep stock parts for 8 years, I had once read. Japan itself seldom values its great watch models, and it is to the credit of collectors outside of Japan who latch upon wonderful diver models and perpetuate their existence for us by gathering rare spare parts and offering their expertise in fixing the oldies but goodies. Japan does not fix older watches past 8 years or so. IMO it is just their cultural habit, usually, to scrap all older watch parts etc. ...kinda sad. I have taken in some of my older divers (7548s and 6309s etc) to my old Japanese watchmaker and he always tells me that there are no parts for these old divers!
Rereading your question again, you ask why there seems to be few 1990s divers other than the Kinetics and 7002s. There was the SUS line of analogue watches, all midsized and targeted to the youth of the day who were weaned on digital watch time. These are great watches but midsized. So, many American collectors who are bigger boned, found the SUS watches too small except for the caliber 4S12/15 ones which became cultish models to the West.
The 7C43 of the late 1980s transited into the 1990s and became 7C46s.
Not pure divers, but the Fieldmaster series appeared in the 1990s and morphed into the Landmaster series. So, you see that there were some great models around in the 1990s but which did not appeal for as long a time as the venerable 6105s or 6309 series divers.
