The only way to earn money past the initial offering of mobi was always in the development, and I have always been a strong advocate of this. Flipping domains would only last just so long, as these names have no traffic nor do they warrant large sums without... development. It is true that it doesn't have to be a dot mobi to work on mobile devices, hence why I also use a lot of dot com's too.
There are pictures too
http://losers.mobi
I have a responsibility to spend the money earned from mobi each and every month on aged whisky, a harem of cute escorts, a box of cuban cigars and my tailor who has the remarkable ability to source exquisite cloth.
Perhaps you could start your very own support group / forum for those who didn't make money with not just mobi, but the entire spectrum of tld's out there, as that may ease that monkey on your back? Who knows, it could be your true calling?
BTW I am still buying one word dot mobi domains and although I will not pay much, everyone is welcome to send me a pm with prices.