The Israelites are a fussy bunch.
On the one hand, these righteous people "speak the truth," "do not slander," "stand by their oath even to their hurt," and "do not take bribes" (15:2-5). On the other hand, the "righteous will rejoice when they see vengeance done; they will bathe their feet in the blood of the wicked" (58:10).
Recap: these are good people who really like mass murder? Basically, yeah.
For the People
The Biblical writers are creating these poems to be chanted amongst their own people. That means any criticisms leveled at the Israelites are done carefully. This is a different ball game, designed to hold people together rather than divide them. It's all about building community
Often the Bible depicts God as having been accepted by the Israelites when he was rejected elsewhere: "The stone that the builders rejected has become the chief cornerstone" (118:22). There's also a sense of validation (22:4, 22:22); because the Israelites accepted God's law, they carry the responsibility to carry and pass it on (145:4). Only they can do the job: "Will the dust praise you? Will it tell of your faithfulness?" (30:9)
But back to the question: the Israelites don't come off as the nicest crowd. Sure, they write pretty poetry, but they're kind of whiny, majorly vengeful, and kind of exclusive. On the other hand, they are God's chosen people and they're kind of in dire straits through a lot of this. How do you feel about the Israelites?