You don't have to, but you are saying that you need to upgrade.
> Every other company offers upgrade paths but not Microsoft.
Many companies are moving to a SaaS model. Some, like Adobe and Autodesk, don't sell perpetual licenses at all. For engineering software you've always had to pay maintenance fees.
> Had I known earlier they don't care about small devs I would have bought something else.
Community edition is free for individuals and five licenses for small companies.
I get that you're disappointed that you can't upgrade for a cheaper price, but the perpetual, or standalone, license isn't for people who need upgrades and it says so clearly on the page (which might not have been there when you purschased it though):
"If all you need is the current version of Visual Studio Professional, you can make a one-time standalone license purchase. If you need new versions of Visual Studio Professional, access to Visual Studio Team Services, or have short-term needs then the Visual Studio Professional monthly subscription may be a better option."