So the question is, to paraphrase, Is fondant edible?
The answer is...it depends.
There are many, many people out there who dislike fondant immensely and many have good reason. Everyone has memories of going to some wedding or celebration with a fondant covered cake on display which can look fabulous (unless you see the ones on Cake Wrecks-those can be utterly horrifying sometimes) but in reality tastes positively horrible. The next fondant covered cake they see reminds them of that previous experience and then they never touch any version of fondant again. Another less common reason that some people dislike fondant is that it can taste too sweet to them, it is a sugar paste after all. Fondant should taste about like a marshmallow-vague hint of vanilla, sugary, that's about it.
Fondant can become frosting for cakes, it can be transformed into beautiful flowers, amazing bows and ribbons, characters and designs limited only by one's imagination-look at the Cake Wrecks on Sundays to discover the magic that can be unleashed in the right hands.
If fondant is used as frosting then it usually is edible, when it's used for decoration-such as fine flowers or frilly bows more often than not, it isn't. Basically a good rule of thumb to follow is that when the fondant has dried out unless you like things very, very crunchy-don't eat it.
Another thing to keep in mind, when a person wants the frosting of a cake to have a really intense colour; the amount of colour it can take to get such deep intensity often will impart an off flavour to fondant as well.
There are tons of recipes to make fondant as well as many commercial brands available, with varying degrees of quality, flavor, and ingredients depending on what application one uses it for.
If a person is going to have a cake made using fondant, ask to taste a sample if you are using a professional bakery to know what the flavour is of the fondant used.
If one decides to make the fondant at home, try out a few recipes ahead of time (and I EMPHASISE the ahead of time part-if you've never made it before, it can be a bear to make workable in a timely fashion) to find one that works or find a local decorating supply store that has some available.
Remember, if you still can't stand it, you can always eat around it ;)