Strikingly similar are the consequences of the mismatch between the CEO and his business at the Gap and Yahoo.

Pressler apparently didn't understand fashion well enough to make crucial retailing decisions at the Gap -- and apparently also failed to appreciate this consequences of this gap and appoint a fashion czar to fill that vacuum:

During top managers' final reviews of the products for an upcoming season, Mr. Pressler -- a former Walt Disney Co. executive who often acknowledged that understanding fashion was not his strength -- simply asked questions about the merchandise, rather than making decisions. After he left the room, his charges huddled and, like Kremlinologists, tried to deconstruct his remarks and reinterpret them as orders. As a result, they frequently fussed over trivial issues such as how the woven shirts should be folded, or whether the legs of the khaki pants should hang off the table. A larger sense of direction never became clear.

The second-guessing and arguing over minutiae have led to bland merchandise, driven away executives and added to the sense that Gap is stagnating, according to former employees. Gap's same-store sales, which are sales at stores open at least a year, have declined compared with a year earlier in all but two of the last 24 months.(wsj)

As with Pressler, Semel has failed to learn technology well enough to lead Yahoo's search and advertising upgrades and integration in a winner-takes-all contest against Google:

But now, despite Semel's achievements in Hollywood and early success at Yahoo, Silicon Valley is buzzing with a familiar refrain: Wouldn't an executive with a little more technology savvy be a better fit? Semel has been Yahoo's CEO for nearly six years, yet he has never acquired an intuitive sense of the company's plumbing. He understands how to do deals and partnerships, he gets how to market Yahoo's brand, and he knows how to tap Yahoo's giant user base to sell brand advertising to corporations. But the challenges of integrating two giant computer systems or redesigning a database or redoing a user interface? Many who have met with him at Yahoo say he still doesn't know the right questions to ask about technology. "Terry could never pound the table and say, 'This is where we need to go, guys,'" one former Yahoo executive says. "On those subjects, he always had to have someone next to him explaining why it was important." One could have made a convincing argument two years ago that such deep technical knowledge didn't matter much. But now we have empirical evidence: At Yahoo, the marketers rule, and at Google the engineers rule. And for that, Yahoo is finally paying the price.(wired)