People need to understand that a photographic camera is not a computer, although it has a computer in it . The speed of advances in computer technology is much greater than in other areas of electronics, optics, video , etc... The mentality of the user 1Dx is a long-term investor, while the mentality user SX50 is much more immediate, and relates only to short term. Generally, investments in Canon or Nikon DSLR and lenses keeps giving the expected return by the end of expected lifetime. On the other hand, Sony has treated its DSLR users in the same way that users point and shoot, with updates in short periods, and programmed obsolescence. A good example is the Sony flash shoe (reversed) that was recently abandoned, and left old users angry with the prejudice to have Flash incompatible with current cameras. Those people who expect huge advances in DSLR every five years will be disappointed. I still wonder what Nikon planning when replaced D700 (12 megapixel) by D800 (36 megapixel). This was a risky strategy that displeased many Nikon users. I'm sure Canon will release a camera with more than 30 megapixel, but will continue to offer 20 megapixel options such as 6D.
I'd tend to agree with this, it looks like the camera business will gradually return to something more like the environment we saw though out the latter part of the 20th century. Less rapid growth, more repeat sales of lenses and other accessories to a loyal existing customer base. As you say this kind of business just isn't part of Sony's corporate DNA, they've always been a company chasing the latest tech trend but the photography business depends on customer loyalty far more than one off purchases like Hifi's, TV's or phones.
We here so much about mirrorless being the future but for me mirrorless as we see it today is mostly companies who lost out on the core DSLR business being forced to go after a much riskier market based on trends that may not be sustainable.