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

Question

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 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?

Answer 1

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.