It is used to describe the reason.In this dialogue:
A: Raigetsu no shain ryokou irassharanai n' desu ka?
B: Ikanai to iu wake de wa nai n' da ga, amari ki ga susumanakute ne
Can anyone explain why the final verb is te-form?
So some explanations maybe silently joined on but they aren't spoken, because profuse explanation is not good (in many situations in Japan).But here nothing is being joined on.
This is a good explanation. There are a lot of cases in Japanese where phrases are abbreviated for politeness' sake. For example, if someone presents a dish that you cannot eat, a simple ちょっと (chotto), accompanied by apologetic body language and tone of voice, can convey the message that there is no way you can eat that food.But 'amari ki ga susumanakute ne' has "te form" so it means reason, and this form, ending with te-form of reason, express apologetic feeling, so often spoken with apologetic intonation.
( I don't know the technical grammer or derivation, but I guess ending with te-form is derived from the abbreviation of series of conjunction which is used by the interrogee to explain reasons or situation.)
So some explanations maybe silently joined on but they aren't spoken, because profuse explanation is not good (in many situations in Japan).
Or by ending with te form ,you may imply the exist of many explanation, it makes no difference if you really have reasonable ones or not, because it is abbreviated.