Buckling springs are always noisy (you can reduce but not eliminate the noise by putting vibration damping materials inside the springs). "Clicky" switches like Cherry MX Blues are always noisy. Other key switches are much quieter, and most of the noise comes from operator error. You're not supposed to press them all the way down like a membrane switch. The operating point of mechanical key switches is near the middle of the travel. If you press too hard they'll bottom out and make a lot more noise, as well as tiring your fingers more. If you're prone to doing this by accident you can fit soft o-rings around the keycap stem to cushion the end of the stroke.
The problem is "buying it wrong" a seller like wasdkeyboards (or others) has dropdowns for half a dozen types of Cherry brand switch and a couple dropdown options for sound dampening o-rings.
At home I use an original model M and I'm quite happy with it and frankly it just isn't that noisy. If people don't like the noise, the problem is they're packed in too closely; perhaps my loud breathing also offends them if they're that deeply invading my personal space.
