Bitcoin is one of the most ambiguous currencies in the world. Certainly, there is Zimbabwe Dollar, a currency used in toilet paper’s stead, as actual toilet paper is worth more than itself, and, when used, it has way more backing.
Zimbabwe Dollar’s reputation is a fine example of what may happen when an economy collapses. Still, you may like to buy a 100 trillion dollar bank note just for fun.
Bitcoin reputation was spoiled not by any economic collapse, but by some of its users. Just like any other thing, we may use bitcoin both for good or for bad.
In this context, the dispute on whether bitcoin is good resembles the dispute on guns. Fans of pistols and rifles are quite right when they say that it’s people who kill, not guns. Their opponents are right again when they say that hadn’t a killer had a gun, the wouldn’t have been a murder with some gun. The same problem happened to bitcoin: you may use it go get paid for a job, or to speculate at an exchange, and similarly you may finance terrorists or buy drugs.