It’s because the MX switch was invented by cherry and they were they only ones you could get up until recently. When then clones first came out, particularly khail was mentioned a lot, they had quality issues. Sticky keys, not smooth travel, chatter causing multiple presses, these were worked out pretty quickly and now yes many of the clones are ever bit as good or in some cases regarded as better than Cherry.
It is only the past few years that clones have come out
As a side note I have a batch of Gateron switches with a flaw that was fixed, the housing around the stem is just a little small so catches the bottom of the key caps where they attach to the stem sometimes at certain angles. So not all perfect all the time, cherry have a reputation for consistency just not out right top quality all the time.
@ProSonicLive as people have said liner are pretty quiet, especially if you do not bottom out the press and hit the cap off the switch.
You can get the mentioned silents that help with that, it they are pretty expensive and only available in certain boards which are also very expensive compared to other offerings with regular linear switches.
Tactile switches are also silent n that they do not clock but do have a bump on the stem to let you feel when the key actuates, these are also quiet though you do get a little more “rumble” as the bump is registered and the extra vibration is passed into your desk. This is easily mitigated by having a desk mat or other soft thing under the keyboard, also helps with the thump from bottoming out linears.
To get the same effect as the MX Silent switches you can get O-Rings that you put under the keycaps and they take up the impact between the cap and the switch, though only do it on the down stroke, I believe the MX silents have rubber on the down and up strokes.