Steem used to exist without sbd. Sbd was created to stabilise steem since it was going way down hill some times ago..
when i say leaving sbd in peril, i mean that when the dust settles after pump and dump, the coin usually has to sit at the bottom of the ocean for god knows how long.. because you cannot stop dump and sbd might as well be looking at the price tag below 1$ after the dump (IF that happens)