Who is right?

Using "for" to mean "because"

1. Interchange 3 Teacher's Edition 3 page T.B 81 unit 12
by Jack C. Richards (Author), Jonathan Hull (Author), Susan Proctor (Author)

1. For + noun or ( noun phrase)
It`s famous for its music.
MTV is well known for its music awards show.


2. An A to Z of English grammar and usage by Geoffrey Leech, page 148
You can use "for" instead of because only before a clause
Example
1. The village was full of crowds of people dressed in brightly-coloured shirts and summer dresses, for it was the middle of the tourist season < writting only>

Can you help tell me who is right,  Richards or Leech.

 There are at least 10 definitions for "for" as a preposition.  See http://www.merriam-webster.com/dictionary/for and other definitions when used as a different part of speech.