The creator of litecoin Charlie Lee supported it, talked with the necessary people and implemented a plan that no one had any real issues with hence it was approved sealed and a done deal.
https://www.cryptocoinsnews.com/litecoin-creator-charlie-lee-urges-jihan-wu-to-signal-for-segwit-antpool-obliges/
(Also the transaction capacity was not near the 1MB limit yet so a lot less impact they have more time to study things later)
Bitcoin the foundation and other groups suggested it met pushback and hence we had a blockscale debate on the best implementation due to a variety of political monetary and strategic issues that scaling presented and the transaction limit was approaching so issues and debate hence drama.
Unlike litecoin bitcoin has no center and its creator was hiding in the shadows and does not appear in public. This is one of the major reasons why activating segwit will take a very long time. Another thing is that there are different groups having different sides and will have their own code and will not stick to segwit. To make segwit activated there is a need for a consensus, but a consensus is very hard to get thus UASF is created to make sure that everything will be in favor of the bitcoin holders. With UASF in the picture segwit activation has become possible. But in order to reach that far the bitcoin community has encountered many problems and challenges.