Jstreet has a definite right of criticism, but like in a family the criticism has to be in house, when you bring an outside judge to the table, then you endanger the family. And that's exactly what Jstreet did by supporting a UN resolution. By doing so they put themselves outside the family.
Turkey's pro-Kurdish opposition says targeted in blasts, toll may rise (Reuters)
from the article: Israel’s problem is the settlements, not J Street