Why did David Cameron resign?

Politics can often be brought down to 2 principles; perceptions and narratives. When David Cameron conceded and decided to hold an EU referendum in order to appease UKIP's right wing voting base, he did so in order to secure that voting base in the hopes that they will vote for him in the 2015 general election, which they did and he won a majority government, which helped him continue to rule as Prime Minister. Thus when he held the referendum and firmly supported to remain within the EU and lost, the result was catastrophic for his position as Prime Minister, he had lost all authority, several members of his cabinet who campaigned to leave automatically gained credibility for leadership of the party and could contest against him. This left him alone to deal with the crisis of leading the first country to ever leave and revoke its membership of the EU and knowing that the probability of failing was much higher than that of succeeding, he bowed out by resigning, thereby hoping to leave the fate of the country in the hands of those who caused Britain's withdrawal from the EU.