I believe there's a lot of commentary, both Jewish and Christian, on this, but if grain sacrifices had been understood as being by their nature unacceptable, they wouldn't have been offered in the temple, and they were.
Anyway, 1:7 mentions "polluted bread" and the verse is a complete thought; the blind, the lame and the sick are mentioned separately in 1:8, presumably imperfect animals. Sounds to me to mean that bad grain and flawed animals are both unacceptable.
So it seems. Older Judaism (Torah) has God demanidng animal sacrifices. See Genesis 4:4, 8:20-21, 15:9-10, Exodus 20:24 , 29:11-37, Leviticus 1:5, 23:12-18, Nummbers 18:17-19, Deuteronomy 12:27.
On the other hand, middle period and apocalyptic Judaism written afterf the Babylonian captivity and closer to the time of Jesus says otherwise. See Ps.40:6, 50:13, 51:16, Isaiah 1:11, 66:3, Jeremiah 6:20, Micah 6:6-7
The same anti-sacrifice sentiment is expressed in Matthew 9:13, 12:7 with "I will have mercy, and not sacrifice."
This indicates a profound change in Judaic mindset, frlom the erly, basically pagan reigion, to Christian-like Psalmology.