You don't have to buy a subscription... they aren't forcing you to buy anything in a subscription model that you don't want.
You can still buy the boxed version and a perpetual license if you'd like. YES, you do have to "sign-up" for an account that is a "free subscription". What this gives you is access to all of the standard content that used to come on the DVD's... clip art, fonts etc. You also have to have a Corel account and be signed in to get updates now. There is no extra cost for this.
Now, if you'd prefer to have access to the additional premium content, you can pay monthly for this subscription, or yearly. Premium content gives you more clipart, fonts etc, but also early access to new tools that will be released in the next version. For example, X7 has the QR Code maker now... this was available in the first update to X6 for premium users, nearly 2 years ago.
Now... if you do pay to upgrade, and then decide later you'd like the premium membership, yes... you pay for the upgrade and the membership. But if today for example you signup for a premium membership... either monthly or yearly... you don't have to pay the upgrade price AND the membership, just the membership.
In May of last year I decided to move from X4 to X6, and I did so with a premium membership. I simply purchased the membership at the yearly price, downloaded the trial and signed in. I had all the standard content, plus premium content, extra tools etc. When X7 was released a few weeks ago... I just simply downloaded and installed it. There was nothing more to pay for, no extra costs or upgrades.
There are some really good threads on discussions on the Coreldraw.com website regarding subscriptions, check them out.
But no one is forcing you to pay for premium content that you don't want, and if you don't want it... you don't receive anything less than if you buy a "boxed" version.