Security (okay "privacy"), also goes the other way...  In the future; (I expect near future), all official/commercial payments will be digital.  This means of course YOU can be financially cancelled as a person, at any time by governments and businesses.  YOU can be black-listed in the real world.  Persona non grata. Your bank accounts froze, debit cards, credit cards frozen, your bitcoin account black-listed.  Perhaps your great grandad owned a "slave", and your whole family gets black-listed.  Perhaps you own real estate that was once stolen "conquered" from another nation.  Maybe you are caught eating dead animals (meat).  Maybe you were peaceful protesting somewhere.  Maybe somebody calls you a racist.  Who knows what "normal" today is that will make you a villain/target in the future.  Regardless of reason you will be a target for future black-listing; privacy is really important, and a natural feature that all good cryptocurrancies should automatically solve.  No smart person shows the world their wallet full of cash, nor bank/financial transactions.  Why would anybody purposely seek out a cryptocurrency (bitcoin) that does exactly that?  Bitcoin can't be everything to everybody.  But to grow up and be a real world cryptocurrency, privacy seems to me should be the high priority.  I can't solve this issue, but if somebody with the ability created a hard-fork; I'm certain the "market" will choose how to sort it all out.