Maybe a cultural thing.
In Master-Tier EUW in flex queue only 13,8% of the teams surrender. In Korea there are 45,8% of this games wich end with surrender. Even - admitted - we don´t know if they for example typically surrender 20 seconds before nexus would be down.
Well. The people wich surrender don´t want to play if behind. Perhaps they are unable to play if behind but I think it just makes not much fun for them or the other way it makes much more fun to stomp themselfes. Being a 10/2 Rengar wich can go where he wants and oneshot everyone is much more fun then a 2/10 Rengar wich has to hide in bushes for not dying.
That´s the main point PRO surrender. The only one, to be fair.
There are several points for never surrender. Some minor as the fact that you can play longer with your champ as the time in queue, champselect, loadingsscreen is lost time. But there are major points wich are mathematically based.
You are not interested in maths as you belong to the 10/2-Rengar group. Anyway. Maybe hard for you but you asked.
Let´s take this numbers for a short calculation as a starting point:
Average match is about 30 minutes. Surrender-voting possible at 15, average surrender time we take the mid and therefore minute 23. Match would have last 7 minutes longer. Let´s assume 6 minutes from queue into match, leads to 36 minutes altogether for a whole match (6+30min). We further assume a 50% winrate and have a look on 200 matches. 100 are wins 100 are losses and half of the lost matches (=50 matches) are "Korean surrender matches". I guess we can (conservative) assume that 2 of them could have been wins. I think the real share is higher but 2 are ok for a short calculation and are good to show others.
Results:
- 2 more wins within 200 matches are a 1% higher winrate
- If surrendered 50 matches with saved 7 minutes each are 350 minutes saved. 36minutes for a match as above assumed leads us to 10 more matches for the group of surrenders.
- To make "saving time for more matches" plausible in terms of "more chances for winning" this 10 additional matches must not end 50%/50% or 5w and 5l but must compensate the 2 wins wich passed because of surrender. The winning quote must be 70%.
Conclusion: Surrender is a good option for all with winning rates of 70% and above.
You can go for 1 win out of 50 surrenders (=60% winrate needed) or 3 (80%) it will not change. It will only give a hook if you go for let´s say 1 win out of 100 surrender votings wich means 1 time within 400 matches. But that is obviousely not fact.
All others belong to the 10/2-Rengar-group. That´s all about that. They don´t know more about the game but avoid difficult and bad situations. Admitted.... 48 times 7 minutes each getting stomped is maybe not for every young mind a good thing. So I can see the point. But mathamatic is not harmless..... and don´t mind.