My guess is that unless a rabbi is a public teacher, there is no reason to publicize his learning.
'Kabbalah' is from a root meaning 'to recieve' and all of traditional Torah is a 'recieving' from teachers. The better expression might be 'sohd', which means 'secret' or 'hidden'. It is 'hidden' in the sense that it is very difficult to understand - like complex mathematics - and easy to misunderstand, because it uses words (that sometimes have ordinary meanings) instead of specialized symbols.
Rav Kaduri (Google him) is an example of a true 'kabbalist' who is known. Most public 'kabbalists' are just huxsters. Many more students and masters just learn quietly.
Isn't Madonna a kabbalist now? Seriously. I'm pretty sure that's what I've been hearing.
And my screen name here, ReagansRaiders -- guess what inspired the "Raiders" portion of it. I've got the official Stetson manufactured fedora put out in '89 for "The Last Crusade" and even have the original "Last Crusade" movie poster they sold at the theaters in '89 when it came out. I guess I'm a bit more of an expert on Indy than Endy is. ;)