Bad company corrupts good character
Before I say anything, I agree with the title above because it's true that you become who you surround yourself with. It is important to have company that makes you happy.
However, I think that SDAs (some or maybe most) take it to an extreme.
It's frustrating because imagine meeting genuinely good people in your life. Along the way, some individuals may broaden your perspective in life. But of course, once a minor change is noticed, everyone's saying you're long gone. Apparently, there is only one right way in life?
People outside the denomination can be good and even more of a blessing than those within. It's frustrating whenever "outsiders" are assumed to be bad influences of character and whatnot. No wonder many SDAs are socially stunted and inexperienced.