Question you need to ask, what is the 100 representing?
People try to relate the 100 as if it is over unity payments. Whereas the 100 is a relationship to Farming Rate and not anything else.
The real question no one asks then is what FR really in relation to the economics of the network.
To answer your question.
Payments are related to farming rate because farming rate is the “need of the network for more resources”.
So in essence it is upto 125% times the need for resources.
Once you realise that then there is no problems. Just the network asking harder for resources.
Now to answer what should be asked by people
The economics have been dealt with in a couple of topics and one explored the age old trick question that if you keep halving and adding then (1+1/2+1/4+1/8+…) what is the result? It approaches 2
What we really need to be exploring is if payment for uploads will cover paying for “need for resources”
To answer that accurately we would need a crystal ball. But we can look at historical use of data and what data people might store.
- History shows that the most accessed data is public new data (ie new vids, documents, tweets, facebook messages etc etc. Compare yours & friends usage of the internet, do you look for the old stuff or the new stuff?
- What will people upload. Well it will be different types
- backups - private
- family photos/vids - private with sharing to a select few
- cat vids - public and random usage - That is new viewed often and old viewed above norm
- messages, tweets, social media - data gets old and unused very quickly
- movies/music - ages reasonably quickly
- How many copies of popular uploads will occur? It is likely the more popular a piece of content is the more people will upload it again, as a message, saving it in their private area, etc
- As the network grows the duplication of uploads will grow too and these averages will decrease too, meaning that more income occurs with without a corresponding increase in downloads.
- etc
Basically one can expect a fair portion of private uploads which is viewed rarely (compared to public) Anywhere up to 40% of data will be private.
Then of the public material a lot will be viewed rarely because only a few find it interesting, and some will be popular for a day to a week (news vids, memes etc) and some popular for a month or so
Now comes the crystal ball analysis 
It is very possible that over 60-70% of all material uploaded when averaged out will be accessed about 2-3 times, because things like backups are almost never accessed. the other 30% is ranges from average of say 10 to 50 times per upload of items. And remember that dedup only means the extra copies are not stored buy the network still charges for the upload. And caching keeps the number of accesses where farmers/devs/ptd/ptp are paid down a lot, that new release (crowdfunded) movie will most likely be cached for the first week and result in very few reads.
It is very possible that averaged across all uploads the number of farming accesses will be very low. Maybe as low as 2 , maybe 5
So then the question that should be asked is how FR relates to upload cost and not how 125 is greater than 100 since the 125 & 100 related to FR, not the upload income.
So we could view accesses according to above crystal ball analysis or take the halving question and say that all content will be access once in the first period of its life then 1/2 the next period, then 1/4 the next, and so on which results in all content averaging out to being accessed twice as much as the first period. Which would give us about the same average when considering the desirability to download.
TL;DR
As long as 125% of FR (average) after coin attempt algorithm is less than 100% of upload income then all will be fine. The coin issuance “algorithm” slows down issuance as coin is issued and not returned quick enough.
And that most content upload is rarely accessed and thus very little GETS and rewards, so pure income. The rest may be rewarded more than its income, but is covered by caching and rarely accessed content and duplication.
And because as more coin is issued the more people will upload the more chance that duplication of uploads occur.
Its unknown at this time how well the algorithms will work well, but the driving force for the rewards is to encourage storage to increase and encourage use of the network.
