Well, Mason's aren't the only secretive folks out there. Wiccans and Pagans will be secretive as well about many things.
In my mind, the secretiveness of Masons is NOTHING to be fearful of, NOTHING to go creating bizzare and rambling conspiricy theories about (although they DO make interesting reads). I personally akin the secretiveness with that displayed by the Gentleman's Clubs of Victorian England. Just because they could. Cause it's fun to be part of something secretive.
Also, perhaps it's due to the simple fact that yes, in the year 2005, despite our best efforts, people still go on 'witchhunts' against those who they have little understanding off. And what I do know about Masonic rituals, they are a little strange to the outsider, and probably to a few insiders. Don't believe me on that? Look at your own post.
Look at the average Westerner's outlook on Islam as a whole right now.
Basically in my mind, Masons are a boy's club, similar to but likely older than Kinsmen. They do good works in the community (I used to work for a Mutual Fund Company and we often donated prizes to many a Mason charity event for cancer, kids, hospitals, you name it) and have a few beers together and network.
Nothing scary. Nothing 'controlling the world'