That doesn't mean much, those domains are just used for URL shorteners. It's not like they are desperately needed.
Many other extensions are also used for the same purpose.
For example, Google own no_url_shorteners but there isn't a market for the ccTLD of Greenland really...
I'm afraid this discussion slightly moves to the whole topic of domain hacks marketability
Well, let's discuss it a little:
1. There are companies who use hacks as main domain. I know that many of NP members are against this practice, but it still exists (i.e. Voya.ge, Frid.ge, etc.)
2. There are companies who have long names and use domain hacks for their main keyword. Good example of it is TeenagePaparazzo.com which is also owner of Teena.ge
3. Of course, there are companies with presence on Twitter or Facebook and they definitely need branded URL shortener (Oran.ge, Mortga.ge, Mira.ge, Enga.ge, etc.)
4. There is also Tumblr, who acquired Pa.ge, but frankly speaking I still don't have any info why
So, to resume, as they are buying that names, others may do it too.