I am just looking for the technical reason of "Why VMware VM cannot have more than 60 SCSI devices?"
Because a virtual machine support only 4 virtual SCSI adapters and each adapter supports 15 virtual SCSI target, so 4 x 15 = 60. If you need more, you can use the virtual SATA adapters. More info: https://www.vmware.com/pdf/vsphere6/r60/vsphere-60-configuration-maximums.pdf
I knew this....but my question was the technical reason of supporting maximum 4 scsi adapters?