I delivered Shalach Manos today to a number of people. Much to my dismay, everyone accepted them graciously and gratefully, and not a single person expressed how disappointed they were with my gifts. It seems clear to me that you should hate every gift you receive, as the verse says (Mishlei 15:27):
שונא מתנות יחיה
One who hates gifts will live
and דברים שבלב אינם דברים - thoughts that are not expressed are not considered (Kiddushin 50b), so this hatred should be expressed and declared.
Is there any explanation for this practice?