Fine, but this is on the buyer not on the seller.
I mean, if you buy a subscription to something and then don't use it (or forgot to cancel while not using it) is not really a seller fail: you would have wasted your money even you'd have bought it without a subscription.
I get subscriptions are (mostly) bad, but it is not always a seller fault and the buyer should be aware of what he is doing or spending money.
I don't disagree on that.
Maybe, but at this point I doubt that a forgetful customer would pay attention to it. What would really make the difference would be to renew the subscription explicitly. This way you could be forced to sign for a false free trial, but you would also need to confirm a subsequent subscription.
Yes, this is another way to see it. But the solution in my opinion is not to eliminate the concept of subscriptions. The solution is to educate the customer.