first of all I want to ask from whom u get this information?
get your facts clear & then do blame anyone.
Shakti left again cause she was not getting her due. ArSha themselves agreed that there r no scenes in script for them.
she is a ace dancer who make herself recognised & achieved many things with her own heardwork.
& if she will being treated like a side character then defo she will leave cause she has many things to do..
many opportunities r there for her & she has right to choose best for herself..
& about palki why u just hear one side of story? don't come on conclusion from one sided story.
Shakti came back cause her fans wants her back & wanted kriyansh story to complete which was ended horrifically by previous creative.
channel brought her back cause fans wanted. that's it.