On PoW chains you can "invest" x money (burned by paying for hardware resources) to gain control over the network (51% attack)
On Steem you could do similar attempt by taking control over enough SP to vote for witnesses. Currently you have to risk value of your "investment" for 13 weeks. With 5 days, attacker (well, you can't even call him that way) can chose good moment (favorable market conditions, etc.) to take control over Steem platform with relatively low price and risk.
Keeping higher (current) lockout time for SP to be eligible for witness voting would solve that issue.
FTFY
Otherwise, I completely agree. This is an additional security issue that has heretofore not been well characterized.
Thanks!
In my envisioned implementation, the bonus VESTS for longer staking would be tracked separately and not be used for voting rights, just financial incentive.
I think @gtg's point is that the bonus VESTS should count toward voting, and maybe the penalty for shorter staking, at least when it comes to voting, should be quite high. (Not expressing my own view here, just pointing out how I read it.)
Either way, it is fairly trivial to implement. You either add the value or don't. It is not significant to the implementation, only the design. The design is in a very early stage (we are still focused on SMTs).
Vests should be vests.