Yes, presidential campaigns can be costly, and most likely everyone who runs for president does so with the intention of winning. However, running for president is also a good way to gain recognition, which can be helpful. For example, if you want to be successful as a politician, you will gain a lot of exposure just by running for president, which will probably help you in future political campaigns. The longer you stay in the race, the more recognition you will earn.
If you want to stay in the face with less than 1%, go right ahead, knock yourself out. After all, it's your time and money that you're throwing down the toilet, not mine.
In all reality, if you can't get at least 10%, you have no realistic chance of winning, so why bother?
Like Lindsay Graham, anyone with less than 1%, or for that matter 3%, should drop out of the presidential race. Theoretically, it is possible to that all the top candidates die or get eliminated for a reason or other and the 1% candidate becomes the top runner. But until that happens they are just a distraction and a waste of time.
Political campaigns are very costly to run; they cost major tax dollars and private capital. I believe that if a political candidate has little to no backing, and therefore a very unlikely chance of winning, they should drop out of the race. That way, any additional funds that would have been needed to finance their campaign can be reallocated to areas of greater need.
If you have less than 1% in the polls, you should definitely drop out. All they are doing is wasting more money by staying in the race. This money could be used for much better things. In addition, they are distracting from the candidates that have realistic chances of winning.