schraf, it's not about secrecy. It's about sanctity. There is an area of the temple that only specific people can be in. I can't say much about this as:
1) It's a sacred subject that isn't discussed outside of the temple
2) I haven't been through the entire temple, (just the baptistry) so I can't really say.
If it makes you feel better, I've been excluded from weddings too. It's hard to understand, but trust me, we encourage family ties, even out of the Church.