That's the point. DENIC isn't doing this for themselves. They do this for *you* (and for me, and even for Randy).
The Red Cross Society is also doing it for *you* and for me and even for Randy. But that doesn't make their network special. If DENIC really wants to build a special network then they should share that special network with other TLD operators. Then I would be happy to support their requests for IP addresses. But if they are not going to share their network then there is nothing special and they must buy service on the open market. I really do want DENIC to build their anycast network. But I want them to share it so that all the other important TLDs don't have to build their own separate networks all doing the same thing as DENIC. In fact, now that DENIC is selling resilient domain name hosting around the world, I would be interested in having them host my second level domains as well.
So putting up the anycast servers somewhere where half of the internet might not see them is not useful. For maximum resiliency (against DoS and outages), one wants to spread the anycast servers over as many different (!) networks as possible. And this cannot be done without a dedicated prefix for it.
I agree with you Gert but this is such a good idea that every TLD will want to do the same. You need to either outsource this to a company that specializes in anycast hosting or you need to separate DENIC into a hosting network business and the .DE name registry business. --Michael Dillon