It was easier back in the days of analog. Voltage over a wire is easy to manipulate. If it was the wrong connector, you got an adapter, or a box which stepped up or down the level.
The big problem these days is that everybody is trying to set "The Digital Standard" since there isn't a single one that's universally accepted. They deliberately go out of their way to make sure not only the connectors are different, but the data transmission protocols are incompatible, and/or use a host of different sample and bit rates. It's like if you took all the format wars of the past in one giant battle: 33 vs. 45 vs. 78 vs. cassette vs. VHS vs. BETA vs. DAT vs. Minidisc vs. ADAT vs. DA-88 vs. HD-DVD vs. Bluray vs. whatever... and had all the companies involved convinced that theirs was the only format worthy of history.
It sucks... but it's less of a concern in the Live Pro-Sound universe.
Well... at least it was... until they started pushing digital transmission lines on us. We are thinking about upgrading our main board, and the next one will have converters at the snake box on stage, which will then transmit the audio wherever we want it over Ethernet. But now we have to consider how that will affect everything else down the line. It will be great if everyone else has gear made by Yamaha.
Far, FAR less so if products made by any other companies are involved...
I feel your pain.
Small reason to be thankful, however: I've been assured it's actually much worse in the world of professional video.