Why aren’t BNC jacks common?

I love BNC. Recently got rid of my streaming transport which was an Auralic Aries G2.2, since Auralic went out of business I figured it was time to move on. The inclusion of BNC was a factor I looked for when checking out new devices. Not a deal breaker if it wasn't there, but I noticed that the finalists I was considering (Aurender N20, Lumin U2X, Aqua LinQ) all had BNC. 

Ended up getting an Aqua LinQ and am using BNC to my Lampizator DAC. AES also sounds great, I can't decide between the two. Whichever I stick with, I'll use the other option to add a CD transport in the near future.

The question also could be posed in the past tense as, "Why wasn't BNC more common before for audiophiles?"

Today, between (a) streaming over ethernet or Wi-Fi and (b) and the portion of the community that has taken up upscaling using ethernet or I2S via HDMI cables, I'd be surprised to see BNC much longer in audiophile gear. 

The exception to that might be any product that sells a fair portion of its volume in Japan, where BNC was more common. 

Older Naim preamps used to use a mix of BNCs (for phono inputs), and DIN connectors for line level inputs and outputs.  Not an XLR or RCA in sight!

@carousel 

Not true. BNC connectors have been the standard for 50 ohm cables in electronic instrumentation for many, many decades. Certainly more reliable than the RCA ones.

I am all for adopting BNC as the connector of choice in audio systems (XLR is also good for balanced cables. Reluctance to adopt new ideas has hampered its widespread consumer use and will undoubtedly continue to do so.

Indeed, I am a big fan of XLR. I have zero Cinch-RCA in my systems. Only balanced.