Why Do People Surrender Games With No Trolls In Them?

I just had my massive, hard-earned win streak broken - and a 1v2 double kill be for naught - when my team traded 4 for 1 outside top tier 3 tower. We had an infernal drake (solo'ed by yours truly despite numerous assist me pings) and I was doing well for myself as Vayne. Yes it was against a lot of hard engage, but I had a ton of poke/peel on my side. We were going to outscale them. I just finished my two item spike the second they surrendered. I don't understand why people in NORMALS have such a defeatist attitude let alone ranked.

TL;DR If you have a late game scaling champ (or multiple), for the love of God, do not surrender if one or more of those late game scaling champs is ahead, ready, able, and willing to outplay the enemy team as the game goes on. The enemy ADC was braindead. Their Pyke support kept inting for free and wasting his ult. That game was quite literally 3v5 and yet we ended up surrendering 4 to 1. Take a wild guess who the 1 was. :)

I wasn't salty in-game (I never am). Just had to get this out of my system and ask people not to surrender when things are looking up. I wouldn't have been mad if we had lost two inhibitors and then tried to surrender immediately afterward, but no, we killed four enemies for just my Velkoz support's life, so I don't understand why the surrender when we very nearly aced them (last enemy had already based).

I know it's normals, but come on man why you gotta tilt me with a lack of competitive enthusiasm? What's the point of playing if you're going to surrender when everybody but the Velkoz is positive KDA and doing well? Yeesh!