A hypervisor is just a kernel with a more clumsy API dictated by legacy hardware design. If you have eight services that can fit on the box together, eight processes on one good kernel should offer better visibility and control over what's going on than would eight VMs each hosting one process (along with some uninteresting crud).

VMs shine when you're stuck with proprietary software that can't all be ported to run on the same kernel, then what you're paying for is a compatibility shim that's cheaper than another box. I don't see much sense for software you wrote in-house.