As far as I remember, that part of ido has grown out of code inherited from iswitchb, so I probably just didn't see a need to change something that worked ok for ido.

Iswitchb had this comment in the keymap setup function:
;; generated every time so that it can inherit new functions.
The new patches seems fine to me.

Regards Kim 

> Den 24/12/2014 kl. 18.11 skrev Dmitry Gutov <dgutov@yandex.ru>:
> 
>> On 12/23/2014 04:07 AM, Leo Liu wrote:
>> 
>> Ido's author is not an idiot and AFAIK he is responsive to questions on
>> ido. So maybe ask him first for why it was designed that way ;)
> 
> Kim, any particular reason it was written this way?