nonsuch123,
You're obviously totally out of touch with what's happening in Tanzania. The article you posted your second link to was published in 2012, since when Tanzania has had a change of government and ATCL has had a change in management, with almost all the old senior management swept away.
Sure, some bits of the website aren't yet working properly - I have the same problem with AF/KLM and frequently complain to them. However, I had no problem at all using it to book a flight from Mwanza to Dar a couple of weeks ago at a cost of $90.
Compared with Fastjet, I found the experience much better with a full service flight and everything hassle free and on time