This doesn't make attacking HIVE easier, it makes controlling it significantly harder. Right now it takes significantly less HP to control the consensus witness spots than 5 votes per account (or 1 vote with a slider) would require. That isn't really debatable, it's a fact. Had either of those measures been in place when Justin Sun bought the Steemit.Inc stake he never could have controlled the top 20 witness spots and none of this would have happened.

If it ain't broke don't fix it

Which means it clearly is/was broke and needs to be fixed.