IBM's CEO has a perfect response to her critics

IBM has had 16 quarters of shrinking revenue. CEO Ginni Rometty took over at the start of 2012, so that's her entire reign.

The year before she took over as CEO, in 2011, IBM had $106.92 billion in revenue and $15.86 billion in net income. It finished 2015 with $81.74 billion in revenue and $13.36 billion in net income.

Rometty points out that she is shrinking the company "by design." She's been selling off low-margin or money-losing operations like its commodity Intel server business and its chip manufacturing business.

And she's been refreshing her enormous, aging workforce in major ways, too. IBM employs 380,000 people. IBM has been laying off thousands of workers a year in those shrinking areas while hiring thousands in growth areas of big data, cloud computing, security. She's also been investing in new markets like design and digital marketing.

Some of IBM's actions seem harsh. Like the recent decision to offer only one month severance to some laid off employees, no matter how many years they served with the company.

But other of Rometty's decisions seem visionary, like ramping up her super smart computer service Watson, into a major cloud service. While all the other major cloud vendors are now chasing the machine learning, artificial intelligence thing, Rometty saw the need for that years ago.

She's rolled out all sorts of Watson-powered services, everything from language, computer vision (recognizing pictures) and data insights to Watson Health, a new unit dedicated to bringing machine learning to medical technology.

Has this put IBM in front? She won't reveal Watson-related revenue because she says she wants to nurture Watson. Watson is part of IBM's analytics unit, which generates $18 billion in revenue and has a large assortment of products, including old-school, traditional software

In the meantime, Rometty has some words for her critics, speaking on stage at Reode's Code Conference held this week in Southern California, reports Fortune's Andrew Nusca. Explaining that the 105-year old IBM has retooled itself many times already, she said (emphasis ours):

"It's easy to have an act one and two. Go ahead and have an act three, four, and five. The saying is the easy part. The doing is the hard part."