As a marketer who has administered surveys in the past, survey data needs to be statistically significant in order to use the results, to either publish them or validate them for decision making.
If you were not selected for the survey, you did not qualify or meet their criteria that ensures a statistically significant sample. That can be because they already had too many respondents in your age category, and their goal is to collect an even # of responses from all age categories, for example. It can also be because you live in a geographic area with too many current respondents, etc.
I hope this helps some folks feel better! It's nothing to take personally, but hopefully gives you more confidence in their data ("confidence" -- lil statistics joke there).