It was sort of an over-generalization but they aren't really wrong.

You need a member of the MLS to list your property there. Whether they get a commission or not, technically you did have to use a realtor.

Forgot to answer the following Q...
"So.....does your flat fee come up on a search like that as a FSBO?"

What the agents see when they get listings is a bit different than what you see at realtor.com for example and it shows more detailed information. It will show what the commissions are and there will be a blank space or zero for the listing agent. This is probably the dead give away for agents that don't like to show FSBO's

There are a couple points of common confusion here.

What "the" Multiple Listing Service is can vary from place to place. In some areas it's owned by the National Association of Realtors and in others it's a private company, and in some places more than one Service is in popular use. These are strictly subscription-only to access, and you need to pay a fee and have a real estate license to get that subscription. (So if you want to access the MLS for different states, you need to pay more than one subscription fee and hold a license in more than one state.)

This is not what people are talking about on this forum when they say they've browsed the MLS. Some advertising websites call themselves a "multiple listing service" because they show the properties for sale from "the" Multiple Listing Service, but they are not "the" Multiple Listing Service. "The" MLS is more of a database that also contains non-public information like special showing instructions, if a house is vacant, the type of contract the listing agent has with the sellers, what compensation is being offered to a buyer's agent, etc. It is to your benefit to get on "the" MLS, used by buyers' agents, if you want to attract larger numbers of buyers. Otherwise you are just on another real estate website that individual buyers may or may not see.

That said, the flat-fee services are in fact Realtors offering you reduced services for a flat fee instead of all their services for a commission. Some of them just enter you on MLS, but others handle scheduling of showings, some amount of legal paperwork, or provide the use of lock boxes for you. What exactly they offer will differ with every such service and may differ from contract to contract. You *are* essentially still FSBO, doing most of the marketing on your own, but your contract with that realtor prevents you from signing up for the services of another realtor should you decide you've had enough of trying it on your own. "The" MLS's require an exclusive contract so that no two realtors will be listing the same property.

I think kpfeif was just trying to make the point that you can't change over to using a realtor when you are in one of these flat-fee contracts. Beyond the extent that the flat-fee realtor is helping you, you are on your own.
I hope that helps!

Forgot to answer "does your flat fee come up on a search like that as a FSBO?"

Yes it does. The listing realtor is named, but there's a special designation to indicate that the realtor is providing limited services, and the contact information is frequently "call the seller at..."

Is being marked a FSBO a problem? Not if you are offering competitive compensation to the buyer's agent. Real estate agents don't dislike working with FSBO's nearly as much as they dislike not getting paid fairly for their work. There's another common misunderstanding.

I am listed in the MLS with a flat fee agency. I can cancel at any time for any reason. I searched several flat fee agencies and some allowed you to cancel and others were more strict.

Also - the agent's name and contact info show up in realtor.com and the MLS. But in the showing instructions(viewable by realtors only), the comments state for realtors to contact owner for showings, offers, questions, etc and that the realtor is just providing a flat fee listing.

Also - when the flat-fee realtor gets any calls or emails from realtor.com or MLS, then the flat fee realtor relays those to the seller. (I tested mine with another listing before I listed to be sure that the seller got the referral, and how fast.)

Also some flat fee listers allow a certain number of MLS changes, others charge a fee for each change after the first. Some allow only one photo, others post several photos.

So shop around for the flat fee MLS listing agencies.

As far as realtor.com, there is nothing in the listing that hints that I am a FSBO (unless you look at showing instructions viewable by agents.)

If I sell it on my own, I don't pay any commission but need to let the flat-fee agency know that it is under contract/sold so they can update MLS.

The sign out front and the flyers were made by me and show my contact info(but I put the MLS# on the flyers.)

Also I have my own lockbox that I bought on the www for $27.

Also when I view Realtor.Com there is no address. If you want traffic you need to make sure there is an address. Sometimes the map function does not work well