The main purpose of staying awake during vaikunta ekadasi is to travel inwards. Where is the time to travel? Even while commuting to workplace we can't remain idle either we listen to songs or chit chatting with the co-passengers.
We always honour the word of the rule. We don't honour the spirit( for some of us, a day without "guzzling"will be a hell). The very essence of vaikunta ekadasi is to remain observe consciousness. Because consciousness is enlightenment.
When you are asked to stay awake through the night means just observe, anchor yourself in the unchangeable one.
But, a simpleton would not understand the crux of the matter. He would stay awake through the night, watching movies ( a couple of decades ago, temple authorities used to paste posters stating that there will be a "video show" on vaikunta ekadasi night at some local temple premises.
Remember,that was a VCR era, that too, VCR would've been a hired one. In those times, owning a VCR was seen a "rich symbol" .Invariably, either sampoorna ramayanam or karnan will be shown year after after on the eve vaikunta ekadasi) indulge himself other than spiritual practice . The next day, dwadasi, our simpleton will be suffering from severe constipation because of "whole-night-vigil" experienced previous night.
I still do not understand the correlation between sampoorna ramayanam and vaikunta ekadasi.