Fair, but shareware was pay-once, which many people find preferable to a subscription-chained model.
There is a big difference between a one time payment and a recurring payment, especially if the company canceling the product or going out of business means you can no longer use the tool, and I honestly steer clear of those in most cases.
And if Canva decides that "I am altering the deal. Pray I don't alter it any further,"[0] what will you do then? Go and rent the Adobe subscription suite instead?
[0] http://www.quickmeme.com/img/32/32b4229145de0a2c1171b9b5757f...