Nintendo released a new model of the Wii late into the console lifecycle, the Family Edition (it was 2011). For whatever fucking reason, they removed backwards compatibility from that model. That's what the OP probably has. I find that a rather dick move from Nintendo, but oh well.
Maybe, but it was certainly based on the fact that few people used that function and the ports only confused the majority of owners. Still pretty stupid to have a BC console and not have the connections.
Still sounds pointless at me. By 2011, the people who get confused at this kind of stuff (aka "the casuals") had already bought the system and were most likely not playing with it anymore. Hell, it was just like one year before the Wii U, so really, why do such a thing? This only serves to annoy people who want Wii with BC because they missed the GC (which, based on the sales of the PS2 vs. GC... was quite a lot)