And some of them perhaps had their .com in 1995.
When was .us released? the .net, the .info, the .biz, the .org? And .mobi was released when?
So I am not sure that is an accurate portrayal of some sort of rationale as to why do they have a .com and a .mobi. It would only stand to reason that if they had an internet presence before September 2006 then it certainly would not only be a .mobi.
Try this instead.
Look at BMW.com and BMW.mobi on your PC.
Then look at BMW.com and BMW.mobi on your web enabled phone.
Or pick any on the list.
Which works best where and which works best on both the PC and the phone.
Stand alone? Why?
Different usage, different format, different audiences, different mediums, different sizes.
Why is that such a bad thing? It is not.
But to answer your and anyone else's question in more detail, rather than bash the extension or members on the forum (not that you appear to be doing this, Creature) ask the companies listed why THEY chose to advertise and use and promote both. Why did they specifically chose to go with .mobi and a new standard of formating to be mobi compliant?
We can speculate all day. Just as someone speculated that if Warren Buffett bought domains he would buy .com (I wonder what brand car he would buy?) we can go back and forth and back and forth.
But those companies are no losers or slouches on a national and international level and certainly know to look at new and expanding markets.
If you ran a mega corporation, would you not have a board or team or underlings looking for ways to retain current customers and give value added service? And you most certainly would be wanting to know and explore ways of attracting more customers. And most likely you would be looking at what your competitors are doing, their weaknesses and strenghts, their advertising strategies, and what is working for them.
That is business. People can chose to be leaders and innovators. Others will follow. But the ones that keep waiting and waiting and waiting to follow will have just that much more of a lesser impact and always remain in the shadows of those leaders.
Very short and quick lesson on business. We all know it is more complicated than this.
But if I wanted to continue running a business like it was still 2000 in 2007, then I would not be in business too long. That is why I suggest go to the source. Most mega corporations have PR departments that would be glad to answer all these questions or may already have press releases on their sites.
Don't take my word for anything.