Most of these people see homosexuality as a perversion, and to have the institution of marriage thrown open to homosexuals diminshes its status.

While this view of homosexuality prevails, the rights of the majority are being subverted by "homosexual marriage"
Are the rights of these people not being affected by having a beloved institution altered in a way which most find offensive?

Most members of the all-white country clubs that predominated until
very recently thought that the membership being thrown open to people
of color and Jews diminished its status.

Have their "rights" been diminished by the (sometimes legally
compelled) inclusion of otherwise-qualified people of color?

Absolutely NOT.

Being comfortable at the expense of denying others equal opportunities
in the world on the basis of the race, gender, or sexual orientation
is NOT a human right.

To position it as such is, once again, the refuge of self-justifying
bigotry, a vile and evil corruption of the notion of 'freedom of
association.'

The racists' (and homophobes) problem is their own racism or
homophobia, not the race or sexual orientation of those whom they
encounter in this world. It is up to them to sort it out; not to rid
their little world of "those people" who make them uncomfortable.

There are human and civil rights which the "majority" doesn't get
to over-rule.