Five times, 20 seconds each time versus on all the time? Gee, yeah,
nobody would want that, would they?
A Human Barb has better things to take than HV. A Human Cleric has better things to take than HV. A Human Rogue won't be taking the to-hit boost because, hey, an extra +3 to Spot/Search/Disable/Open/
UMD! A Human Wizard has better things to take than HV.
Unless the Human has UMD or is a rogue splash build, they won't take HV, because they have better things to take.
Go back to pre-HV change. Every Human build with a rogue splash or UMD had HV. Period.