Being older

I am wondering why once over the mid 50's 60's age you seem to be put on the too old heap. Going to a swingers party/gathering you are shunned and left alone, trying to date on here and other web sites I am way out of the age bracket. Just wondering why. When my ex and I were in swinger we did not have a cap on the age, and found some extraordinary people who were a lot older, now 60's is more like late 40's, much more healthier fitter and have a wealth of knowledge on most things including sex but that seems to be not considered. Anyway that is just an observation and wonder if others see the same