Anas (ra) mentioned Tamim al Dari bought an expensive garment just for the musjid for the prayer. And he also had an expensive garment just for tahajjud!
So it’s shocking to see people wearing pajamas and praying! Especially people who are supposed to be students. Some of the ulema say this is a deficiency in emaan.
We also learn that we should have a portion of the night prayer. Even if it’s straight after esha and just 2 Rak’ahs. A student not having a portion of the night prayer is unheard of.