I'm not in favour of the hereditary principle in principle, but neither am I in favour of having a political Head of State: Parliament is sovereign and a Head of State with a political profile (or, worse, some kind of independent mandate) violates this. A mild constitutional monarchy is an acceptable compromise and preferable to most Republican systems, even if it isn't my preference. Besides, there are more pressing matters.
So what is your preference? A non-political HoS or abolishing the office of HoS?