There are a lot of different ways you can garden, the "traditional" in the ground in rows, raised bed, container, and many others. People on here have piled up tree trunks and let them rot some before planting in them, planted in a pretty thick layer of wood chips, and even grown stuff in hay bales. There are different techniques for each of these. You can grow vegetables, herbs, berries, fruit, and so many different kinds of flowers as you sort of saw on Larisa's thread. We have people on here that have done all kinds of stuff, sometimes successfully, sometimes well not always.
There are advantages and disadvantages to all of these. Annette built her raised beds up high to help her back. I have one like that and I have to water it all the time, being up like that it dries out very quickly. Mine is built up like that because it's in a wet spot, if I didn't have it built up it would be waterlogged. We even have different reasons for doing the same thing. To me you need to try to find a method that suits you, your needs, and your area and then go for it. But be flexible and try to not overextend starting out. Several people make this huge plan and plant a lot, then burn out when they discover what a time and effort commitment it takes. Kind of work your way into it and find the level that works for you. You can get quite a bit of production from a small area anyway, you don't have to go big.
Regardless of our methods I think you'll find a couple of things pretty common among most of us. Most of us are really big on mulch. It takes some effort to get things mulched but there are real benefits to weed control, moisture retention, and other things. I think most of us also make compost. We have plenty of raw materials and that stuff is black gold to a gardener.
I did a quick look at your link and I'll admit, I got a few chuckles for their reasons for raised beds. Most of what I do is "in the ground", not raised beds, so I welcome others with more experience with raised beds to tell me I'm full of it, but I'll offer some comments. You'll find we area friendly group but we often tease each other. Most of us don't take offense, we just get even. Or laugh it off.
Protection - there may be some pest benefits, like maybe fewer cutworms, but don't take this to mean pest free. Erosion, maybe if that is a problem. I suspect Annette sees a big benefit on her steeply sloped ground.
Weed Control - Maybe in some circumstances but I don't move mine. To me any advantages are marginal at best. Some of that may depend on your weeds. My Bermuda grass finds its way into everything.
Better Soil - or worse soil, depending on what you put in. You can amend or replace any soil anywhere.
Better Yields - that depends on so many other things. You can get great yields with any method if you do it right.
Savings on Food and Medicine - Once you get past initial investment, maybe. Maybe not. If you price out your time, certainly not for me. The flavor of your freshly grown stuff is tremendous. You know how it was grown and what went into it. And I just enjoy growing stuff. There are plenty of reasons for growing your own stuff but cost savings don't factor in for me. How are raised beds any different from other methods as far as this goes, especially if you consider start-up costs?
Reduces Back Strain - If you build them high like Annette, yes. If you don't well maybe not so much. A lot of heavy labor goes into building them. Don't make them too wide or you can't reach across. But if you build them right, this can be valid.
They're Portable - Yeah, right, especially after the back strain claim. To me, I see this as the type of benefit where if you ask the person how often they've actually done it, they'll say "well, never".
Efficient Use of Seeds - I don't see where this method makes any real difference in this. It depends on you no matter what your method.
Aesthetics - This depends on how you do it. An artist like Larisa, Annette, Mary and others can make anything really attractive. People like me, well any of it will look rough.
Don't take any of this to mean I'm anti-raised bed. I'm not, in the right circumstances for the right people they are great. I'd guess it's the most common form of gardening used by the people on this forum, some are just not raised very high. I'm just old and cynical, I don't like exaggerated claims, like implying any garden method is pest-free. I could say things like this or worse about any other method. There are plenty of people on here that can give real advice that will actually be helpful.
Again
and I find them easier to tend then the rest of the garden. I have one cut into a slope, waist high on the front side, ground level on the back side, back side has netting for beans, this year the rest of this bed was used as a holding bed for some Iris but I usually grow tomatoes in it. 
so, next year they get the hot spot in case we get another cool summer. 
