Seems you don't like the idea too much
Anyways: When doing an amount of these, like one a day, I actually think we will learn some things. When doing many pictures, not spending too much time on each indivually we get to try out many different combinations, techniques and colors, without too much inconvenience. If we pick new colors in every picture we might get to know the colors better, hues, shades, and dithering colors etc. We may also get a deeper understanding of the most important things of the pictures, and what is best and easiest to do first and so on. We can learn from our mistakes, and trust me, 10 minutes is a lot of time to make mistakes
. When pixeling fast many times we may also learn to use certain techniques fast with a reasonable amount of accuracy. I.e. on the #2 that I colored I practiced to dither a lot, and adding a lightsource. The lightsource is pretty crappy and now that I study it afterwards I can think of different ways to make it better.
About innovation; we have to make pretty fast decisions. Given a theme, making up an idea of what to make and then immediately pixelling it, having to think fast, is good for future use I think.
Also it is fun