Many people who take the Strong on the web are Artistic types. Conversely, Realistic types are much less frequently represented among those who take the test. A person might conclude that Artistic types are more frequent in the population and therefore would be more likely to take the test. That's unlikely to be the case. More probable is the difficulty Artistic types face in finding work that matches their interests.
The latest edition of the "Dictionary of Holland Occupational Codes" lists 12,756 professions. Of that list, 8,465 are Realistic (66.4%) and only 180 are Artistic (1.4%). The simple truth is there are far more Realistic jobs than any other type. Investigative and Social jobs make us small percentages as well (3% and 5%). It's no surprise that those who are interested in these occupations would have a more difficult time finding work than Realistic types.
It's interesting to note the Dictionary lists no occupations at all for these codes: ARC, AIC, ACR, ACI, and ACE. These codes have five or fewer occupations: ARS, AIR, AIS, AIE, ASC, AEC, and ACS. Out of the 20 possible combinations for Artistic jobs, only two have more than 20 job titles: ASE (28) and AES (74).
Let's contrast that with the Realistic lists: There are no combinations with zero jobs. Three combinations have over 1,000 job titles each: RES (1,755), REC (1,343), and RCE (1,824). No other scale has more than 1,000 jobs for a single code. Closest are CRE (677) and ESR with 433 professions.
If we look at two-letter codes, the difference is even clearer. There are 4,027 RE and 2,787 RC jobs. There are six IA, nine IC, nine AI, and two AC jobs on the complete list.
When there is a large number of interested people and few jobs, the increased competition makes it harder to get a job in that field and depresses the pay. An example I often use is actor. Many people would pay to appear in a commercial or movie. If that's the case, how much can an unknown actor expect to make for working in a commercial? Not much, since there is so much competition and many people would do it for free.
As a result, many Artistic types struggle to find work they like. Many work in "normal" jobs and pursue their interests as hobbies or avocations. Others keep trying until they find a place where they can use their talents in a way that is satisfying. Each person is different and has to see what works best for him or her.