Well, you can tell that to all the Nõmme, Tondi, Pirita, Kesklinn, Tartu, Viljandi, Karksi-Nuia amongst other places I've lived where I've smiled and said "Tere hommikust!" to as they turned their face away and pretended I didn't exist.
I've also lived in Amsterdam and even people on the street who were not my neighbors smiled and said good morning and often that triggered a little conversation and laughters.
Like I said, I'm Brazilian and I've also lived in Ireland where people are super warm. There is no "insincerity" and "mindless" assumed, only the desire to make our days a little more bearable, warm and welcoming.
The younger generation is better indeed but they also come with a new set of anti-social behavior. Just like every generation, really. Not blaming either one in here.
The attitude always shifts a little when I speak Estonian, though and for that I'm happy enough. I have adapted but will never stop smiling at the shops or at the people who live nearby. I don't expect them to be like me but I also won't erase myself as if I'm being insincere because I'm simply not. I rather be a positive force for change.
To each their own, I reckon. I guess a good neighbor it's the one you don't talk to.