There are some quite compelling reasons given on both sides here, but in reviewing those instances I can't help but feel that those cases which are justifiable would be quite rare and exceptional cases. Certainly not warranting regular capability, but also making an annual opportunity fairly punitive in some cases.
On that basis, and recognising that this might result in even more DM admin (sorry 

 ) I would propose a process to request a 100% RCR subject to review by DM. If justified (for whatever reason) and validated by the DMs via application, then groovy. It's quite possible that this exists today via DM request, but I'd be proposing a more formal 100% RCR request mechanic as some reasons do seem quite reasonable.
Some examples where I could imagine it might be justified:
1) QC/Technical builds for testing... assuming these were done with some QC brief then 100% RCR seems very fair!
2) Builds where the technical capability no longer works or was changed
3) Some RP-based rebuild. I can't think of any specific examples that would be justified, but appreciate there could be some... 
Some example reasons where it may 
not be justified:
a) Because a new item is different to the selected weapon focus feat tree - I'd suggest that is a re-train, and would RP the usual 30-20 RCR as a re-training period
b) Most changes in RP direction - in most cases either stick with the build and just RP you new bits socially (not all a deities faithful need to take cleric levels, for example, nor do all singers need to take bard levels) or change in line with your RP and except the weaknesses, or RCR as usual and treat it as a re-training period to accommodate the new direction...
c) General desire for new tweakiness 

 we all want new shiny things... but the current RCR mechanic seems a reasonable price for making purely mechanical changes assuming no technical issues (as above) 
I'm not claiming that these are comprehensive lists, just examples, as I'm not smart enough to come up with a complete list. On the basis that none of us are omniscient, a process for requesting a 100% RCR seems a reasonable one.
Personally, I have RCR'd all my epic level toons a few times, Umbral especially has had about 12 different builds now (all fundamentally similar though) and whilst the Epic grind is just that, it also leads to some great RP adventures.