And why are your hands full? Because you didn't take time to think.

Really? If you just take time to think then everything will go nice and smoothly and you'll always have spare capacity? Let us know how that goes for you when you get a real job.

It goes very well for me so far, thank you very much.

good theory is the best tool

Nope. Good theory is just one more tool.

Don't get me wrong, good theory matters. But good, clean design also matters. Clarity of thought (about the problem space as well as the theory) matters. Good tests matter. (Someone said, "It's amazing how many bugs a proven-correct program can have.") Good process matters. It all matters.

No, many great developers have their hands full because they have a number of ambitious projects. Certainly some tasks take enormous effort regardless of your technique.

Also, some don't care to write or proselytize.

Because I inherited a mess.