i like punctual people
This is the exact same sentence.
And it is much more succinct. I don't know why they want to make answers more complicated than they need be, and in this case they add a word that is not even there = 谁 shéi, or who and that just throws you off.
我喜欢准时的人 where is the 谁 ?
'I like a punctual person' should also be accepted.
I like punctual people.