It is not a fair bet to traders because as you say it is a "forced" position, traders have to lock their steem and this is the worst thing for a speculators. There is no way to speculate on steem without getting hit by the inflation which is why traders are not buying it.
This is especially true because, even though as SP investor you have voting rights, the SP is so concentrated with insiders that the voting rights to a new investor, even a fairly large one, are all but meaningless.
I don't see this as a problem at all. The main reason people buy steem power is for the curation reward. The more SP they have the more curation reward they get, so the system is working there. I understand what you mean though, people like to feel that their vote is worth more but this will be solved naturally if the price of steem increases.
This is also why steem power should not be seen as an investment but just a way to increase your steem balance.
EDIT : Actually the main reason people buy steem power now is because they are told its the only way to invest in steemit without getting hit by the hyperinflation.
And the main reason why people should buy steem power is the curation rewards.