You do own the software forever. It doesn't expire after a year; you just will no longer have access to new releases and support. It's their last FAQ item on the pricing page.
It does seem a bit odd to hide that detail on the very bottom of the page. I have other development tools (JetBrains products) that having similar pricing models without signing up for a "subscription" and with a discount for renewing each year. I feel a lot better about that than what Xamarin has presented here.
The JetBrains stuff is also cheaper. I'd love to buy Xamarin just to play around with. But $300 for a single platform, and I don't even get Visual Studio support with it? The idea of using C# for apps really appeals to me. But only because that means I could use Visual Studio and ReSharper.
To compare that with the JetBrains business model. I can get a personal license for IntelliJ IDEA for $200, and there's even a free open source version that does 95% of the things I want with no limits. Their other products also have fully unrestricted 30 day trial periods.
I guess Xamarin isn't targeting indie developers or hobbyists in that field. Which is OK. But it feels a little insulting to have an "indie" license which is so prohibitive and at the same time expensive.
It does seem a bit odd to hide that detail on the very bottom of the page. I have other development tools (JetBrains products) that having similar pricing models without signing up for a "subscription" and with a discount for renewing each year. I feel a lot better about that than what Xamarin has presented here.