The people staying in the race with 4% or lower are worse in the ego dept.
So you're saying people that register low poll numbers should drop out of races?
What about all the grass roots conservatives taking on entrenched politicians? They often start out and stay very low in the polls with the hopes that they will eventually see a surge of support and knock of the incumbent or foe backed by big money. Does it usually work out? No. Does it sometimes work out and they rally and win? Yes.
There is nothing wrong with staying in the race if one has at least an outside shot and is playing the long game. Just ask McCain. He was written off for dead in '08 and came back to win. In this case it was very unfortunate since McCain was a terrible nominee, but he waited for Guiliani and Thompson to implode and then raced up the polls and took the lead for good.