I agree with the main point of your post; however, the part about hygiene I don't necessarily agree with (although 'low' hygiene is relative, so maybe I don't know what you have in mind here).
Low hygiene can actually be bad for one's health. For example, by not brushing and flossing regularly, bacteria can actually affect ones brain and the arteries connected to the heart.
On the precepts of Inner Tantra, Tulku Thondup's Enlightened Journey wrote:"To afflict one's own five aggregates, which are the Buddha families. One should not abuse one's own body but take care of it."
Not to mention that if we're unhygienic/carry a stench, and if people find out that we're Dharma practitioners, they could be driven away from the Dharma if they see us as an example of what Dharma leads to. Of course for some people nothing is ever good enough; so if we're doing our best, and we still don't live up to their standards, then it's on them at that point.
So I'd say at least we ought to find a way to brush & floss regularly; and if one lives in the city, then try to shower a good few times a week. If one is on retreat in nature away from the city, then maybe frequency of bathing/showering isn't quite as important.
And again, 'low' is relative, so maybe I misinterpreted what you mean by 'low hygiene'.