[jarin]

The value is polish.

He's not making a data-driven business app, where a shadow here or a custom icon there are nice but ultimately unnecessary. He's making a piece of software in a field where the small details can often be the difference between obscurity and massive success.

Of course, there are exceptions to the rule (Dungeon Raid, Doodle God, etc), but they became successful in spite of their lack of polish by having excellent and novel gameplay. When you're "borrowing" someone else's successful formula, you're competing with all of the crappy clones out there and need to put in a little extra effort to stand out.

Plus, he's making the game for fun, and it's a hell of a lot more fun to make something you're really proud of.