Yes, you're over-reacting.

Ever see Better Off Dead ?

Roads aren't free, someone gets taxed to pay for them. More pertinently, credit card processing fees aren't free either, and active.com is not a non-profit organization.

The club is most likely using active.com because it is much easier and more convenient for everyone. If they weren't using Active, they'd have to pay someone to prep a website, they'd have to pay for credit card processing and handle customer service issues, and chances are this would end up costing much more than $5 per rider.