The recommendation engine works the other way - it can happily expose people to content that makes them a worse person.
I'll just assume you meant "most people" here, because otherwise it's not an useful argument.
Then this would only be true if one of the following applies:
a. The position you consider "better" can't withstand criticism. (Which I'll just assume you don't believe.)
b. Most people don't want to be a good person. (Probably untrue.)
c. What constitutes a good person is not consistent in your circles and most people have a different understanding. (Unlikely?)
d. Most people can't think for themselves.
Assuming you believe d., let me tell you that most people are probably smarter than you think and are indeed able to think critically. Don't extrapolate from a few noisy but bad examples of humanity.