'Homophobia' is as simplistic an explanation as 'racist' or 'bigot' or 'uneducated' or 'ignorant' (no doubt, some would use them interchangeably.)
I think when opinions vary and conflict so drastically, it is more useful to try to understand and examine the content / reasoning of conflicting opinions and deal with that, rather then dismiss one or the other on the basis of a loaded word which does nothing to address any particular perceived misconception.
For example, there used to be many (and unfortunately, some still are) who dismiss certain opinions because they come from a woman or young adult ('what do they know - they're only a _') .
What it all boils down to is that, if the opinions are different they are dismissed, not usually due to the reasoning, but merely because they are different than the other -and it's too tricky to come up with an alternative view based on dealing with compiling evidence against the basis of the opinion-
There are plenty of people who, with 18 years (or more) of school and university have come to the opposite conclusion as you about the supernatural world, Anon -mostly because school and university are only a fraction of the actual life learning anyone should actually do-
Saying 'I don't believe in it so if you do you're wrong and therefore [insert label here]' isn't really a valid or persuasive argument.
What would be interesting to know is on what basis your faith that there is no supernatural deity is based. This is, after all the essentially most important issue and is only one basic premiss of any argument (on religious grounds) against same-sex marriage - that of belief in a deity. However, there are others that follow - if you accept that a deity COULD be real, then not every person agrees what said deity says about it, so you then have to unpack how you determine what that is etc..etc... The reason we're still debating it today (and will no doubt continue to do so) is because it is complex, and therefore cannot be understood or dismissed in simplistic terms.
There are others who opposed same sex marriage on non-religious grounds (and even same-sex couples who oppose same-sex marriage - are they also homophobic??) , but they are not really the opinions OP was interested in when the thread was started. S/he was talking about the theology of the CoE and whether it could ever reconcile same-sex marriage within it.
If anyone considers that theology 'homophobic' sobeit, but I hope it is because they have come to that conclusion after developing a deep and detailed understanding about the belief system itself in order to be able to thoroughly explain why it is erroneous (or have compelling reasons and evidence why their own world view is the correct one).
Hard to do with such an emotive issue!