Of course, just as it is in any business, there are good Realtors and bad Realtors. But doing your research, looking for testimonials from past clients, etc, will generally help weed those out.
Statistically, you will find that as of 2013, 89% of buyers ultimately bought a home using a Realtor. Sellers know this, so they are using a Realtor to list their home and get their home on the MLS. Now, some buyers think that because of the websites out there that have listings from the MLS on them, that those websites are all they need to find the home they want. BUT. Especially in a market like the one most of the US is experiencing right now, where inventory is low, buyers need to know about listings BEFORE they hit the market... and that is where the relationships and circles that Realtors work within will help. We (Realtors) communicate constantly about real estate. We share with one another, listings that are coming on the market, in the hopes that if a buyer's agent has a buyer looking for that listing we are about to put on the MLS, that they can have first shot at it. Multiple offers on listings are becoming the norm. So, you as a buyer, will be in a MUCH better position if you have a Realtor representing you in situations that, while high-stress for you, are simply part of the process.
I suppose in a nutshell, I would ask "how many homes have you bought/sold in your life?". And assuming the answer is even 1, wouldn't you say that you learned something from that experience that you would remember the next time you bought/sold a home? And so, take that same scenario and apply it to a Realtor that buys and sells MANY homes.. every year. Think about how many different experiences that Realtor goes through, in each sale. And then consider the benefit you, the buyer, would gain from the lessons and experiences they bring with them to help you in your home purchase.
I hope all this helps answer your question. If I hadn't been doing this for over 17 years, I could certainly see myself asking the same question. But I know without a doubt that with what I know from my experience, that if I were a buyer, buying real estate today, I would absolutely, without a shadow of a doubt seek the help and knowledge of a buyers agent.
Good luck!? :)