Capitalism is based on private ownership. Is it really a flaw if it applies badly to an area of public/common ownership? Is a plane flawed because it doesn't fly underwater?
It seems that it would be the fault of whoever is trying to apply it.
It's not like even die-hard supporters of capitalism claim that applying it to public property works well. From Mises.org:
On the contrary, when the individual is merely a tenant, either of
a farm or a dwelling or a business site, his interest is in taking
out all he can to compensate for the cost of the rent he pays. This
is true whether his landlord is a private person or a government.
Actually, in those cases where government has become the landlord,
the evidence abounds that tenants are even less interested in
improving or even maintaining the property they occupy.
It seems an appropriate description. Of course, their solution would possibly be to privatize the seas, which I personally wouldn't advocate for.
