You've learned quite a bit, I hope, about how unintentional and unnoticed biases can sway a survey and produce incorrect results. You've also learned, though you may not realize it, a little tiny bit about how to construct a survey intentionally to produce desired results.
This opens up a whole new ballgame.
If you go into research as a career, you will possibly work for a research firm that gets hired to conduct research for businesses, governments, news organizations, etc. Sometimes they're truly seeking accurate data, perhaps to inform and influence product development, and you need to know how to get it for them. But other times they will want to use research to sway public or customer opinions. Knowing how to conduct a survey to get a result, and do it unobtrusively, is also a marketable skill. (I won't get into the ethics of it here, but I consider it in the same genre as marketing, not science, per se.)
Trust me - when Battlecreek Breakfast Foods, Inc., asks you for a survey, what they're looking for is proof that Krispi-Krunchies is the tastiest and healthiest cereal of all time. The Ironlung Tobacco Company will be looking for data that demonstrates that their cigarettes are quite healthy and that cigarette breath combined with tobacco-stained teeth are considered very sexy indeed.
And when Reid-Hillview airport wants an environmental study, they'll be paying you to prove that lead from avgas is causing brain damage in children so that they can shut down the airport and sell the land to real estate developers. You can read a ton about that fiasco here on PoA.
Knowing that this sort of "research" can be done, how it's done, and that it is done, should make you very skeptical of any studies you read. A healthy degree of skepticism will serve you well.