What is から doing in 不幸の手紙から, 全然進歩しちゃいない?


From the first episode of Death Note:

> 不幸の手紙から, 全然進歩しちゃいない

This apparently means something like

> No better than chain letters.

**Questions:**

  1. I know から usually means "from", but what function is から playing?
  2. Why is 進歩しちゃいない used instead of 進歩していない? I know according to [this post](https://japanese.stackexchange.com/questions/95860/what-is-the-difference-between-%e3%81%97%e3%81%a6%e3%81%af%e3%81%84%e3%81%aa%e3%81%84-and-%e3%81%97%e3%81%a6%e3%81%84%e3%81%aa%e3%81%84/95874#95874) that 進歩しちゃいない includes a (hidden) は in it, which "hints at something else beyond restriction". I'm not sure what this would mean in this context though. Does this hint that while this letter might not be better than a chain letter, it might be better than...something else?



  1. It is mostly a matter of translation. It still means _from_ , or _compared with_. Consider another example: 人間は一万年前 **から** 進歩してない= _People have not changed **compared with/since** 10000 years ago_. The sentence could be translated as _(It) is no different from chain letters_.

  2. It is certainly a version of してはいない, but the difference is rather subtle, 全然進歩して(い)ない sounds practically the same to me, simply しちゃいない being more colloquial.   
That said, the presence of は can be considered as an emphasis. Or (not
exclusively) it indicates the contrast with the common conception that the
opposite is true (in the example, it **is** different from chain letters). For
example, 人間は1万年前から進歩しちゃいない sounds more like the speaker assuming that
generally it is believed that humans have changed a lot over 10000 years.



  1. It is mostly a matter of translation. It still means _from_ , or _compared with_. Consider another example: 人間は一万年前 **から** 進歩してない= _People have not changed **compared with/since** 10000 years ago_. The sentence could be translated as _(It) is no different from chain letters_.

  2. It is certainly a version of してはいない, but the difference is rather subtle, 全然進歩して(い)ない sounds practically the same to me, simply しちゃいない being more colloquial.   
That said, the presence of は can be considered as an emphasis. Or (not
exclusively) it indicates the contrast with the common conception that the
opposite is true (in the example, it **is** different from chain letters). For
example, 人間は1万年前から進歩しちゃいない sounds more like the speaker assuming that
generally it is believed that humans have changed a lot over 10000 years.

