After briefly reading about systemd’s tmpfiles.d, I have to ask why it was used to create home directories in the first place. The documentation I read said it was for volatile files. Is a users home directory considered volatile? Was this something the user set up, or the distro they were using. If the distro, this seems like a lot of ire at someone who really doesn’t deserve it.
Realistically, probably not. If your workload is highly memory bound, and sensitive to latency, you would be leaving a little performance on the table. But, I wouldn’t stress over it. It’s certainly not going to bottleneck your CPU.