It doesn't really matter whether the property you are letting is your primary residence or not, really.

It matters in terms of security. If you're using the property, that either means that you have a considerable amount of personal information and valuables on-site, or that you'll have to take them off-site to secure them.

If the property is a dedicated vacation home, then this will generally not be the case, and coupled with deposits, property insurance, etc, the risk to the owner is significantly reduced.

Good luck getting property insurance on an apartment you sublet.