It's not that he didn't want it used, it's that he didn't want it misused. What God didn't want was his name used in profane, irreverent, or false ways (like the casual American expression "Oh my God!"). Since the name represents the person, God didn't want to be casual, careless, or insignificant. Exodus 20.7 doesn't say not to use the name of God, but not to misuse it.

Some people decided not to use it for several reasons: (1) to make sure it stayed sacred, and (2) if there was punishment for misuse, let's not even get close to that. We can avoid the situation entirely if we never use his name. They're not taking anything away from the Bible, they're just trying to be circumspect with giving honor to God.

If God didn't want his name (YHWH) used, why didn't he keep it a secret? It was originally in the Bible close to 7,000 times, but it was people who removed it and decided to make it secret, even though the Bible says not to add to or take away anything from the Bible.