I followed the link you sent me and, without malice, I want to recommend you not get your health information from the lifestyle section of the Nassau Guardian.
The condition that is mentioned in the article, and has received more accurate media attention as well, is very real, although it is just now being described by researchers and isnt well understood or considered a disease at this point. Its called persistent sexual arousal syndrome (PSAS), or more recently persistent genital arousal disorder (PGAD). Basically these names describe the experience of persistent feelings of genital arousal that is not caused by sexual stimulation and is not experienced as sexual pleasure. These feelings can last for hours or days and can cause extreme distress and discomfort. The article you read makes light of it, but its not a joke for the people who are living with it.
The second part of your question is interesting and a common point of confusion. One of the important issues about sexuality that the existence of PGAD raises is that sexual health and pleasure is never only something that happens in our bodies, and that from an individual perspective, what is most important about sexual pleasure is that it is chosen and/or desirable.
There is a big difference between physical signs of arousal, and the individual experience of sexual pleasure. Genital arousal may mean nothing more than excess blood flowing to the genitals. In some situations this would be a very pleasant thing, but it could be equally experienced as a negative or painful effect. Because most of us are raised with a variety of misconceptions about sex its easy for us to confuse things like physical arousal and sexual pleasure, since were not taught to distinguish them for ourselves.
One of the barriers that women who experience persistent genital arousal talk about is the social attitudes of those around them. People hear about the condition and think that it means you are experiencing desired sexual pleasure all day long. In fact PGAD has led women to depression and thoughts of suicide.
So the long-ish answer to your question is that sexual arousal (or at least arousal of the genitals) isnt always a good thing, particularly if its unwanted and out of ones control. Being turned on is a subjective psychological experience, and, for the record, its one that has to happen consensually, even if you consider it your job to keep your partner turned on, if theyre not feeling it, well, then theyre not feeling it.

