It might sound strange to go all the way down after an already very long day, but this is for your own safety, though you might not realize it at that moment:
- To be really acclimatised at 4600m (the height of high camp Barafu) you need several weeks
- If you did not get Altitude disease when arriving at high camp the day before summitnight, means that the climb schedule has been good.
- it does not mean that you are fully acclimatised, that is impossible in the regular timeframe (5-8 days) to get there. As long as you are not running around camp without any effort (like you are walking at sealevel), you are not acclimatized
- The jump from 4600m (high camp) - 5985m (summit) is too big for everybody, but unavoidable due to the geography of Kilimanjaro. So the chance of getting AMS (Acute Mountain Sickness) is high.
- Most people will get AMS in a light form, mostly as headaches and extreme exhaustion.
- AMS only show itself after many hours, but can be lethal within a few hours more and most victims die in their sleep, often at the same height or even lower than they had slept before without problem
- With AMS the only solution is to descend to the altitude where you are acclimatised to, for most Kili climbers thi sis about 3000m
Do not forget that you had not spent a full night at high camp as you will have left for the summit around midnight. The fact that you did not feel sick when getting to high camp does not mean that you were not at risk for AMS. The fact that you had no trouble with altitude does not mean you would have no trouble if you had stayed at Barafu for a full night after going to the summit.
This is not to scare people away, but to make everybody realize what can happen on high mountains and why the summitday schedules are so long.
Mountaineering is very serious, it does not matter if the mountain is non-technical. Only 2 things can be done to prevent accidents: stay at home or reduce the risks. Going down as low as possible reduces the risks.
It will be uncomfortable, as you will be tired and the tracks are normally very muddy. But it is for safety and the next morning you will only have to descend for 3-4 hours, so that is the positive part!