Consider, if you will, an imaginary photographic equipment market, of about 20 years ago.
Nikon has recently released its top of the range FSLR camera, the F800. This camera uses Nikon's own branded film that has to be processed in Nikon's own brand of chemicals. Also in the Nikon range is a mid range FSLR camera that, likewise, uses it's own NIkon brand of film and chemicals (slightly different from the top of the range film and chemicals). In fact, there is an entire range of Nikon cameras, each model with it's unique Nikon branded film and chemicals, compatible only with the specific model.
Of course, it's not just Nikon. Canon, Nikon's biggest competitor, also has a full range of FSLRs. Like Nikon, each Canon FSLR has it's own unique film format and chemical process. There is no cross-over between products, and certainly no cross-over between manufacturers. In fact, most camera manufacturers require their customers to use brand and model specific films and processing. Only at the low end of the market is there any standardisation.
There are, however, third party chemicals that can be used for all cameras with better quality results, but, these need to go through a lengthy modification on the launch of each new camera model before they can be used to process the film from that model.
All is not lost however, some smaller manufacturers have agreed on a standard film format and chemical process.
Sound crazy? It should do. Perhaps, you could justify this farcical model by saying that the manufacturers are creating an additional revenue stream by locking camera owners into their specific file formats.
*Now*, jump forward to the present day. Film has been largely superseded by digital. As you've no doubt guessed, the 'film' in the above analogy is the manufacturer's proprietary RAW formats and the 'chemicals' are the software required to develop that film. Except, in the digital world, the manufacturers have absolutely no financial reason for maintaining proprietary raw formats. Their own processing software generally sucks and the users have to wait until their processing software of choice has been updated to support the latest formats.
If the above analogy had been true, which manufacturers would have survived the film era and which would now be dominating the digital landscape?