I agree that Greenspun's arguments are disappointingly weak.
I'd like to try to tackle your point 1, since I haven't seen people do that before. I should preface that I am indeed in favor of marriage equality, yet I think that it is incorrect to treat it as a human rights issue, or even an issue of equality before the law.
If you treat it as such, then marriage itself (or, rather, its sanctioning by the state, with all the attendant privileges for married people and corresponding burdens on the community) is an inherently discriminatory institution. Fiscal benefits? Extended insurance? Visitation rights? Why should these privileges be enjoyed solely by married people?
Countering that anyone who wants these benefits can get married is as obtuse as pointing out that homosexuals always had the right to marry someone of the opposite sex. If I am unmarried, why can't I name my cousin as a dependent for health insurance? Why can't I have my best friend immigrate to the US to be with me, instead of a spouse I don't have? What if I plan to be celibate all my life, but have strong platonic relationships? What if, instead, I am a polygamist?
It's quite obvious that, if these are indeed civil rights, let alone human rights, then any individual citizen should be able to enjoy them; and those that necessarily involve more than one person should be applicable to any pairing (or group?) of a citizen's choosing. Why should people who are not in a romantic relationship be treated as second-class citizens?
If, instead, they are not human rights or civil rights, but privileges granted by the state because there is a public interest in encouraging and supporting marriage, then the question of how far and to whom these privileges should extend is a perfectly legitimate matter of debate.
I strongly agree; the entire setup of marriage enshrined in law the way it currently is is just wrong. It discriminates against polygamists, as you note, any certainly other groups. The societal rights and burdens of marriage should definitely be available to arbitrary consenting parties.
Even more so then, that the genders of the parties involved are completely irrelevant.
I'd like to try to tackle your point 1, since I haven't seen people do that before. I should preface that I am indeed in favor of marriage equality, yet I think that it is incorrect to treat it as a human rights issue, or even an issue of equality before the law.
If you treat it as such, then marriage itself (or, rather, its sanctioning by the state, with all the attendant privileges for married people and corresponding burdens on the community) is an inherently discriminatory institution. Fiscal benefits? Extended insurance? Visitation rights? Why should these privileges be enjoyed solely by married people?
Countering that anyone who wants these benefits can get married is as obtuse as pointing out that homosexuals always had the right to marry someone of the opposite sex. If I am unmarried, why can't I name my cousin as a dependent for health insurance? Why can't I have my best friend immigrate to the US to be with me, instead of a spouse I don't have? What if I plan to be celibate all my life, but have strong platonic relationships? What if, instead, I am a polygamist?
It's quite obvious that, if these are indeed civil rights, let alone human rights, then any individual citizen should be able to enjoy them; and those that necessarily involve more than one person should be applicable to any pairing (or group?) of a citizen's choosing. Why should people who are not in a romantic relationship be treated as second-class citizens?
If, instead, they are not human rights or civil rights, but privileges granted by the state because there is a public interest in encouraging and supporting marriage, then the question of how far and to whom these privileges should extend is a perfectly legitimate matter of debate.