I'd say as the market of simmons lovers gets older, their sales have dropped heavily. Just read the stories posted in this thread, all old cars when you were all younger.
Let's face it, they are an old school wheel designer/manufacturer mainly suited to old school rides, and as the modifying scene has dramatically changed over the last 10 years, it would have impacted on their sales.
Most of the young performance car owners these days have probably never heard of them or if they have, don't like the designs.
Evolution I guess. Either that or Tony just wanted to retire and enjoy not having to run a business.
Will these guys be next??
http://www.dragway.com.au/splash.asp - I remember when I was in high school, all I wanted was an HQ with a supercharged 350, turbo 400 gbox, 9in diff and a set of dragway's wrapped in BF Goodrich Radial T/A's!!!
Those were the days!