I don't particularly care what did or didn't work in Bitshares. what we have here is working here (at least this part of it is). That's what matters to me. As I suggested to @recursive, you should leave your Bitshares baggage there and approach Steem as its own platform with its own strengths and weaknesses, which it is.
The job of the witness is to witness all transactions that users make and record them into a block
This is absolutely incorrect as I noted in my comment. The job of witnesses certainly and inherently includes other functions and while it isn't necessarily inherent that it also include funding of initiatives, development, and personal contributions of time by high qualified individuals, that role is also working well in Steem.
While I do not have personal experience with Bitshares, I do know that Dan has written a few things about his experiences with Bitshares and how things that did not work well there informed his design for Steem. Apparently stakeholder voting on individual funding tasks did not work very well there given apathy, lack-of-expertise, and lack of coherent vision on the part of many stakeholders. By vesting a group of well-qualified, reliable, and trustworthy well-paid witnesses in Steem to personally perform or hire-out/delegate these functions in Steem, these and other well-recognized problems with direct democracy are avoided.