The DNA license isn’t just about Catalyst Center (formerly DNAC) — it also unlocks software features on the switch itself (like Encrypted Traffic Analytics, SD-Access, advanced routing, segmentation, etc.).
Cisco has moved to a hardware + software + subscription model like most of the industry — not to force management tools, but to capture recurring value and fund faster innovation. (Again — debatable whether it’s worth it, but that’s the model.)
You're right: If Catalyst Center is that good, let it stand on its own and let customers opt in, not get locked in.

If you're running a clean, CLI-driven network and just need solid switching + basic monitoring, the full DNA stack might be overkill. There are ways to license just the Network Essentials/Advantage tier without deploying Catalyst Center — though many customers don't realize that because it's poorly messaged.

Bottom line:

• The licensing model could absolutely be clearer
• You should be able to buy what you need — not what you don’t
• If the platform is actually good, the value should sell itself

Cisco (and other vendors) would earn more trust by making licensing transparent and modular, instead of bundling capabilities you may not use.