Dear Gert,
When this policy was initially written, there was a) no experience with sub-allocations, so I was careful, and b) worries that this might lead to LIRs sub-allocating all their space out the window, and then ending up in lengthy discussions with the NCC hostmasters - so a barrier was built in that was reasonable for the time and the envisioned usage ("customers that run ISP-ish businesses and need larger chunks of addresses to handle their customer allocations themselves").
While we still do not have much experience with sub-allocations, the warning "if you hand it all out, you might not get new space easily, so be wary" is moot - it's now "if you hand it out, there will not be any more space, period!", and LIRs should have noticed *that* by now...
I think for now all LIRs know that IPs in RIPE finished and they understand what they do if they will sub-allocate all IPs. And may be it make sense. For example, in Russia you need 1,5-2 years from incorporation until receving all permissions (licenses, etc.) from goverment to provide telecommunication services. In this case company can sub-allocate all space for some time. -- Kind regards, Alexey Ivanov