When I reference Israelis, I include Israeli Arabs, as they Israeli voters. That quite a chunk to take out of the equation, or calculate it separately. And still, for all them figures, it's a poll. A Palestinian publicly advocating strong pro-peace, or accepting Israeli point of views, risks his life. Israelis are (still) free to do that. I'm not sure how replying to a pole compares with actually engaging in such activity.
With regard to the decline in support for this among Jewish Israelis, we've been over the issue of the shift right, and of religious elements gaining strength quite a few times.