The saying “The world is but a canvas to our imagination” by Henry David Thoreau is right. But imagination is a very but a very difficult thing.
I think that making card decks from templates is a good pastime and fun.
I'm in agreement with you that it would be a fun and interesting thing to do for one's own entertainment or as part of a DIY project you put together at home. However, it's only a matter of time before someone decides that they want to make a deck for public sale and distribution and, lacking the talent or any other affordable means by which to create the design, they will use this template, this "card making machine" for lack of a better term, and Kickstarter will be rife with cookie-cutter designs made from this Photoshop plug-in.
One or two might even be good enough to produce, but the bulk will be absolutely terrible, clogging up the works and making it more difficult to find the diamond in the rough amidst the lumps of coal. All deck projects will take a hit as a result, should this actually come to pass in a big way - there will be too many deck projects to sort through and the critical, casual deck purchases that happen by serendipity and random chance will become more scarce than natural diamonds. Without those kinds of purchases, there's hardly a deck project in the top ten all-time fundraisers that would have raised the money needed to reach their goal, never mind the lofty heights they've achieved.