I'm just a bit allergic to unnecessary dependencies and Guava is a massive blob of a jar. It's not properly modularised so you can't just pick the bits you need

I'm just a bit allergic to unnecessary dependencies and Guava is a massive blob of a jar. It's not properly modularised so you can't just pick the bits you need, if you want to use a single feature from it you have to include all of them. This can cause problems if someone who wants to use your framework also wants to use a different version of guava. In general the fewer dependencies your framework has the easier it is for people to use it.