This is not about Steam. I purchased it from Steam, so I own it.
Yes, you own the Steam version of the product - where the Steam client is required to install and use it. When you purchase any of our products on Steam, the Steam client is required to install and use them. If there is still some misunderstanding of how that works, how better can I detail it?
If you purchase a software product (not a game) from our Stardock store, there is no need for a client to install them. If you want a version that does not require Steam, you would need to purchase it from our store. I would be willing to offer you a coupon to do so if that interests you.
Stardock Customer Service Manager