Not all Real Estate Agents are crappy FYI. Its just a handful who are really unethical. One just have to be careful when choosing the right agent to market one's house.
Having worked as a Real Estate Agent before, let me highlight a few problems.
1) If there is a ruling on the min education level (ie O Levels) , then will be a lot more unemployed ppl roaming the streets.
2) Not all agents are unethical. Most that I came across are good professional agents who are unwittingly blamed by owners / buyers. ( I will elaborate on this later)
3) There are a lot uneducated sellers / buyers in the market who simply cannot understand the importance of appointing sole marketing rights.
For point 2, take this as an example. Seller wants to sell house, he appoints an agent. The agent will advise seller on the prevailing market price and TOGETHER, they set the selling price after making sure that the price will cover any o/s loan and/or have a balance money that is comfortable for the seller.
Agent then markets the property, conducts viewing and successfully secures a buyer for the property. The buyer makes an offer lower than the expected selling price. The agent then tells the owner about the offer and awaits the owner's decision. Then the owner decides to sell at that price for whatever reason. The deal is secured. Few days later, owner's neighbours managed to sell his house at a higher price (maybe better renovation) then owner accuses the agent for not being professional.

Because he did not secure the best price. The irony of things is that, the agent never force the owner to sell, the owner decides on his own account to sell at that price.
This works the other way round for agents serving buyers.
Personally, I have gone through this problem at least 3 times myself. Everytime, it ends up with a complaint letter to my agency and once even to Institute of Estate Agents. Guess what was the result? Owners must remember this.... AGENTS CANNOT FORCE YOU TO SELL. UNLESS YOU HAVE PROOF THAT THE AGENT PUT YOU THROUGH DURESS.
For point 3, owners always think that by asking 5 agents to market their house, they will get it sold faster. Please lah... 1 good agent is better than 5 agents who will use your unit to market their own unit. FOR OWNERS WHO THINK THIS IS RIGHT, LET ME ASK YOU... HOW MANY LAWYERS WILL YOU ENGAGE TO FIGHT A LAWSUIT FOR YOU? And so, the question comes back to the owner ( all the average Singaporean )
How can you expect agents to be professional when you don't treat them like a professional just like lawyers and engineers? Great thought? Think about it...