‘Their drink has become sour, they play the harlot continually, her rulers dearly love shame, the wind has wrapped her up in its wings, and they will be put to shame because of their sacrifices.'
Hosea now provides the reasons why Israel are to be avoided. The first reason is because their drink has become sour, not literally, but because of their disobedience and unfaithfulness to YHWH. Drinking was a major part of their feasts as they ‘drank before YHWH' (compare Exodus 24:11). But now it is no longer to be seen as religiously satisfying, or as a contribution to spiritual blessing as they join in worship, but is to be seen as ‘sour', and as bringing judgment and condemnation on those who partake. We can compare how Paul warned that to drink of the wine at the Lord's Supper would bring judgment on those whose hearts were not right and who treated it casually (1 Corinthians 11:27-29).
The second reason is because they constantly ‘play the harlot' by lusting after the Baalim. By doing so they demonstrate their unfaithfulness to YHWH, even if they do introduce Him and His Name (‘as YHWH lives') into their rituals. Thus they are unacceptable to Him.
The third reason is because ‘her shields (i.e. her rulers/defenders) dearly love shame.' The thought is that even the leadership, and those responsible for their wellbeing and protection, lust after shameful things rather than after YHWH. They love what is shameful. Note the change from ‘they' to ‘her', the former representing the children of Israel, the latter Israel as an entity (their mother - Hosea 4:5). Hosea regularly changes from singular to plural and back again when speaking of Israel, even in the same context.
The fourth reason is because, as a result of their false sacrifices offered at the high places, Israel has been ‘wrapped up in the wings of the wind', that is, are finding and will find that the winds of destruction are blowing heavily upon them, and will eventually carry them away from their land. Depending on the date of this prophecy they had already experienced something of this (or would soon) when part of their land had been turned into an Assyrian province, with many taken into exile (2 Kings 15:29). One day it would happen to them all (2 Kings 17:5 ff.).
Some, however would translate as ‘spirit' instead of ‘wind' (compare Hosea 4:12) with the idea being that they are borne along by ‘the spirit of licentiousness' (whoredom).