It's all a bit infantile, isn't it?
It's like any tool. In infantile hands, it is infantile. In mature hands, it's a useful and helpful tool.
Use it to help monitor and manage your online reputation.
If you have either a small number of both applauds and smites, or a small number of posts, don't worry about it. The sample size is too small to mean anything and likely to be skewed by a single unfortunate post or a small number of "smite-ers."
If you've got a fair number of smites and applauds, say an aggregate total of 50-100, look at the ratio and use it to gauge your reputation. It's like a political candidate's approval rating. At a minimum, you want to be in the positive numbers. Ideally, you might get around a 3-2 or even a 5-3 ratio of applauds to smites. If so, you know you have a pretty decent reputation on the forum.
If you are underwater or at about 50/50, you might want to reflect on your posts. Ask yourself if you are being rude or dismissive to others, are you posting reasoned opinions or solid information? Or, are you making a lot of "drive-by" comments that are either uninformed or denigrate others?
The sample is non-scientific, but the larger the sample size the more accurate the rating is likely to be. I would say that anyone who has a few hundred posts and an aggregate of applauds and smites that exceeds 50 or so can get a pretty good idea how others on the forum feel about him or her. Some people may not care and may even take pride that they are unpopular, but I assume most people want to maintain a good reputation among a group of people that in some ways is a peer group.
Okay, so for me personally, who do I smite and who do I applaud?
I applaud people who are helpful when I ask a question (that's just common courtesy).
I applaud people who offer unsolicited tips that I find helpful or who seem to go out of their way to help newcomers.
I applaud people who offer reasoned, well-thought out arguments, especially if they are espousing an opinion that is contrary to conventional wisdom.
I am much more generous with newcomers than with old hands, especially if the newcomer is generating undeserved smites.
I smite people who are rude or dismissive to others, even if they are technically correct. There is too much internet bullying and it's my way of sending them a message.
I smite people who express ridiculous opinions solely for the purpose of stirring things up and causing problems.
I smite obvious trolls.
I am more harsh on those who post a lot, because they should know better and, especially, if their incessant posting is aimed at stifling or demeaning newer participants.
"These are may principles and if you don't like them, I have others."– Groucho Marx