Telephonic Interview in Mncs

I had on interview for Automation testing in Silk test two weeks before. Interview was happened around 45 minutes through the manual and some automation frame discussion.
HR again called me for the 2 nd round techinal. it was went through fine around 45 minutes.
Next week , they called for Face to Face interview in the form of metting the manager. After going there, i realialised they have three more round. Again they are asking question from basic.
Basically what reason they have the telephonic round? they want to filter the candidate through telephonic round?
Worst thing happening in the s/w industry. they are unnessary wasting the Candidate timing.
Just ,I shared my experience here. Because i cant scold any body directly.