Peloton is both a product manufacturer and a service provider; setup fees are common with many service providers. For example, if you bring a phone you bought elsewhere to your carrier, they'll charge a fee to activate it for their network.
That'd be like Apple charging you $75 if you wanted to use iCloud+. It makes used products less valuable, which ultimately hurts your brand image in the long-term, even if you might be able to boost services revenue for the next quarter or two.