[Avodah] why did Chazal cancel shiva bc of Yom tov

[Rich, Joel]

That has reawakened in me the question of why did Chazal cancel shiva
because of Yom tov?
======================================
As one who sat shiva at the cemetery on erev Pesach, I tried to keep in mind R'YBS's insight into true simcha as being lfnai hashem (which is what we're supposed to be on shalosh regalim).  Seeing it through HKB"H's eyes it's all good (we are human and so don't experience it as such).  So: She-nir'eh et nehamat Yerushalayim u-binyanah bi-mherah ve-yamenu,  which will allow us all to see more clearly
KT
Joel Rich

THIS MESSAGE IS INTENDED ONLY FOR THE USE OF THE 
ADDRESSEE.  IT MAY CONTAIN PRIVILEGED OR CONFIDENTIAL 
INFORMATION THAT IS EXEMPT FROM DISCLOSURE.  Dissemination, 
distribution or copying of this message by anyone other than the addressee is 
strictly prohibited.  If you received this message in error, please notify us 
immediately by replying: "Received in error" and delete the message.  
Thank you.