They pulled a massive bait-and-switch on their first users. Overnight, without notice, they changed their long time published pricing from pay-as-you-go (fee per transaction) to high monthly fees. For many, the cost was orders of magnitude higher. They arbitrarily decided the API would only remain accessible if you bought the highest priced plan.
It'd be fine if they gave notice of the change or grandfathered people in, but at least initially, they didn't. They just wrote condescending, insulting blog posts telling us all how we should appreciate their rate hikes. If you weren't happy with (or able to pay) the higher prices and had already integrated Recurly with your site, you were essentially held hostage. They have all your customer billing information, not you. If you want to keep billing customers, your revenue!, while you strip out Recurly and implement some other payment system and get all your users to sign up again, you've gotta pay to keep your account open in the meantime.
Eventually they figured out that screwing with their users like this wasn't a good idea after all, backtracked and came up with a new pricing scheme more like the original, but it's really too late at that point. Revenue is what makes a business. You don't play games with who you trust that to. And nobody should ever trust it to Recurly, since they're more than willing to play games with you.
If you want to outsource subscription management, check out Spreedly and Chargify. They've proven themselves more trustworthy than Recurly by far. Really, I recommend doing it yourself though, it's not that bad. PayPal subscriptions and IPN can take you a long way with minimal coding.