One thing I prefer not to do is tote a lot of stuff on my commutes. I want to keep it simple, basic. Flat repair tools, something for lunch and work attire, if need be. Thats about it. I can get all that in a backpack or bag, about 2/3 the size of the one shown on this bike.
I know everyone is different, and we all have our own wants and needs. Local weather might dictate your load, for example. I live in South Carolina, where the weather is generally mild. Elsewhere, who knows?

I think the derailleur cover is a pretty cool idea, however!