For 막— , how does "rough, low quality" semantically appertain to "last, final"?

Question

The meanings of "rough, low quality" and "last, final" feel UNrelated to me. What semantic field underlies these meanings? Just because something is "last, final" doesn't mean it's "rough, low quality". English has the adage "save the best for last"!

막 - Wiktionary

Etymology 1

Contraction of 마구 (magu).

Adverb

막 • (mak)

1. Synonym of 마구 (magu, “carelessly, wildly”)

Prefix

막— • (mak-)

1. rough, careless, of low quality

Etymology 2

Prefix

막— • (mak-)

1. last, final

Answer 1

They are different words, but coincidentally have the same form / pronunciation. This is why they're listed as "Etymology 1" and "Etymology 2": having different origins (etymologies). This is called '동음이의어' in Korean, or 'homonyms' in English. An example in English would be 'bark' (the sound of a dog) and 'bark' (the skin of a tree).