And in the world of photography.
If you jump ship today... sell off all your Canon or Nikon gear and then 2 or 3 years down the line Sony BetaMaxes/Vaios/XBRs the Alphas and sticks to making sensors and other devices for other manufacturers... what happens to your gear? Will you take a huge price hit trying to get back into Nikon / Canon or who ever is now the market? Or do you just say how great your camera was back in the day and try and justify that you don't need the latest.
No. For any (real) professional photographer, their gear are tools. Only, they are tools that must be kept up to date to provide their clients with the best possible product. This means that even if a professional photographer does stick to one brand (e.g. Canon), she/he will anyway be replacing their gear in three-four year cycles.
For example, any professional photographer worth his/her salt have upgraded their 24-70mm from the Mark I to the Mark II. Same with the 70-200mm lens. The same will be with the 100-400mm lens. Now when we start looking at cameras, we see that real pros have all upped from the 5D2 to the Mark III. Or from the 1D4 to the 1DX.
So if a real professional photographer is anyway constantly replacing gear as new models/marks/versions are introduced by their chosen brand, then it becomes a small mental jump to realise that "switching" brands (or rather "mixing" brands) is not really such a financial disaster as most enthusiasts think.
Therefore, if a real professional photographer "switches" to Sony and Sony terminates the product-line after three years, then the professional just "switches" to another brand. He/she then uses that brand, possibly upgrading within it for a few years ... and then maybe "switches" again.
On the other end of the scale, most enthusiasts, nearly all of which have invested in lenses they do not really need, will take a financial hit. But then, they've already set themselves up for that hit due to GAS.Did I take a financial hit when "switching"? No ... actually, I came out of the deal with heaps of extra dinero because I realised I did not have to replace certain lenses due to (a) me not using them very much and (b) a replacement lens incorporating the abilities of at least two-three previous lenses.