This all seems sensible until Adobe revokes your license and you lose all money you invested so far and access to the work you produced. There should be consumer protection laws for these cases. When you pirate software, everything works smoothly (unless you catch some trojan), but if you are a paying customer, all kinds of unpleasant and artificial problems are thrown at you.
Or just let the consumer vote with his money. (sketch and pixelmator look like they're growing nicely) All "protection" laws will do is add compliance costs and increase the barrier to entry.
