Why does it say "Gefen Bokek Yisrael Pri Yeshaveh Lo"?
Rashi #1: Yisrael resemble a vine that drops its good fruits. So they abandoned Me - I am the good fruit that they enjoy, and benefit them.
Rashi #2: The fruits of their deeds caused them to be like a plundered vine (bereft of its fruits).
Radak #1: They are a vine without any moisture. Bokek 1 is like "Bukah u'Mevukah" (Nachum 2:11). Enemies plundered it and made it like an empty Kli. How can it succeed, and increase children and property?!
Radak #2: Yeshaveh is an expression of Shav and Sheker, i.e. the fruits will be false, like "v'Sirosh Yechachesh Bah" (9:2; they will not produce like expected - Radak there).
Malbim: After mentioning that it was decreed that they go to Galus, it explains how it occurred. Hashem put on them frenzy and rebellion against their kings. They rebelled against Shalum ben Yavesh and killed him, and afterwards slandered Hoshe'a ben Elah to Melech Ashur, that Hoshe'a sent messengers to Soa Melech Egypt. These two kings did not cling to Chatas Yaravam, and those who clung to it stood against them. This caused Melech Ashur to come against them first in the days of Menachem ben Gadi, and at the end of Hoshe'a's days, and he exiled all of them. Yisrael are compared to a vine - "Kerem Hayah li'Ydidi b'Keren Ben Shamen" (Yeshayah 5:1). Hashem planted this vine, "va'Ykav La'asos Anavim va'Ya'as Be'ushim" "va'Ykav l'Mishpat v'Hinei Mispach li'Tzedakah v'Hinei Tze'akah 2 " (ibid. 2, 7).
Radak (Yirmeyah 2:22): "Gefen" can be masculine like here and "va'Yimtza Gefen Sadeh va'Ylaket Mimenu" (Melachim II, 4:39), or feminine - "uva'Gefen... v'Hi k'Forachas" (Bereishis 40:10), "l'Gefen Aderes" (Yechezkel 17:8), "ha'Gefen Nochriyah" (Yirmeyah 2:22).
Malbim (here and in Yeshayah): Hashem hoped for good grapes - Mishpat Bein Adam l'Chavero, and Tzedakah Bein Adam la'Makom. They produced sour grapes. They stick houses together, in order to steal from the poor. The poor scream due to their oppression. In place of a proper vine, Yisrael are "Gefen Bokek" - it casts down the fruits proper for it.
What is the meaning of "k'Rov l'Firyo Hirbah l'Mizbechos"?
Rashi #1: When I influenced good on them, and they made many calves for Mizbechos.
Rashi #2: They made Mizbechos and caused evil to their assembly.
Radak: When I increased their fruits and made them succeed in property and children, they increased to make Mizbechos for Ba'al.
Why does it say "[k'Tov l'Artzo] Hetivu Matzevos"?
Rashi: They increased Matzevos.
Radak, Malbim: I benefited their land with grain, wine and oil, and they persisted to erect Matzevos to other gods. Hetivu is [an expression of very much,] like "ha'Heitev Charah Lach" (Yonah 4:4).
