I think the question should be do you care about people seeing your phone from a certain angle/distance. For me, it's ok for people to see what I'm doing with my phone except when it comes to an extent that they'll be seeing my password or bank account.
I think good viewing angle does mean a superior screen but since i'm looking at a device head-on, i don't really care. Like Mr. Jerry mentioned, if it's a tablet or something bigger, i would really mind since it's meant for multiple audience.
I used to think that viewing angles were just full of crap, and didn't affect my smartphones performance to me. However, after getting the butterfly i can tell you that viewing angles are an absolute yes. Its not really about how far you can view (i dont care about 180) but more about the colour reproduction at the same level. Although some phones have poor viewing angles, it is perfectly fine to use when your face is directly aimed at it. However, with many of my friends smartphones even with the slightest turn it starts distorting the colours, giving an awful experience. So yes, it does matter.