Why? The issue was whether dispensationalism envisions God's warth being poured out upon millions of people living in Israel during the futurist "great tribulation". It plainly does as the comments by Walvoord and LaHaye demonstrate.
The question is, do you agree with their interpretation?
God's warth upon those living in Israel (as well as the rest of the world btw) during the tribulation period is very clearly evident from scriptures - both OT and NT.
The real question is what part(s) of the Bible do you really believe, or is God lying here in Zech 13.