Except a dial combination lock is a dedicated security device that you purchase for the sole and consciously chosen role of securing something. A better analogy would be the gas cap on your lawnmower coming with a combination lock - how many people do you think would bother to change that one...? It has nothing to do with digital - it's all about the balance of perceived consequences ("Huh? What did you say DDoS stands for? And my kit is doing it? Really? Whodathunkit...", aka zero) and risk ("Yeah right, of all the people, the Russkies are out to pop my router...", aka zero). Darwin award candidates notwithstanding, most people are fairly good at protecting themselves against well known, proven threats - in that sense, the attitude is perfectly adjusted to the typical real-life consequences to the owner: none.