The palpable fear that Apple evokes in Silicon Valley is getting worse by the month.

As long as Apple keeps designing products that consumers love, the company is practically untouchable.

Yell "Apple!" in a theater crowded with Silicon Valley executives and watch how fast they head for the exits. Or, more realistically, drop the name into an interview and suddenly even the most long-winded marketing manager is speechless.

This has always been vexing for me because the fear creates an iron curtain past which only Apple-sanctioned information can pass, at least in the U.S.

Pretty much every person at every company that I talk to is under special orders not to utter a syllable about Apple. (I say "pretty much" because there may have been one or two cases that I'm not recalling.)

What's going on here exactly Though this syndrome is not news in itself, it seems to be getting worse as Apple grows in size and influence.

On the surface, it's pretty obvious. People are either directly or indirectly doing business with Apple and do not want to jeopardize financial ties with the almighty maker of MacBooks, iPhones, and iPads. At least, that's one of the more obvious reasons. And, of course, there's the theory that company executives will often demur anyway when being asked to comment about other companies. But not always. Some executives are foaming-at-the-mouth eager to contrast their company--positively of course--with another.

But, below the surface, the level of fear and anxiety that Apple triggers is unprecedented, I think. And this is made worse by the hordes of oversensitive, hair-trigger Apple zealots who are ready to crucify anyone who offers even constructive criticism of an Apple product. Though I don't know this for a fact, I can only surmise that on some level this reflects the controlling nature of Apple corporate culture.

Sadly, the only meaningful, i.e., critical, commentary I've ever heard about Apple is from a few Silicon Valley executives who always speak under the most strict conditions. In short, that I promise to never report their comments--with the implied threat that they will never speak to me again if I do. So, in this sense, I play my part too.

That said, it's hard to argue with success. As long as Apple continues to crank out products that everybody wants, the fear factor will be there. (And I'll continue to buy MacBooks, iPads, and iPhones.) Oh well.