You know that KKK were killing people right? and anti-interracial-marriage were not allowing people to live together. Do you think that can be compared to prop8 which only wanted to remove tax cuts and social status?
No, what Brendan helped pass was worse than anti-miscegenation laws. With the latter, you might not be able to marry your first preference, but there are plenty of fish in the sea. If you're gay, in post-Proposition 8 California, you could not marry anybody you were attracted to.
Where did I say that? I said that not being able to marry anybody at all you were attracted to is worse that not being able to live with one particular person that you might fall in love with.
Also, marriage has more legal implications than taxation.