To me, Deltas are the type of people who tend to have strong conservative christian values. They're like the people at Starr Commonwealth. Emotional connection between two individuals isn't nearly as important as what is 'good for the community.'
Although completely well-meaning, and not at all done out of hatred and fear, they're more likely the type of people who think that being gay is something that can and should be cured through therapy.
They work hard and have great moral work ethics about ummm working. =p And they like to share long moral conversations at dinner, about how so and so was being wrong or right. The fact that they might emotionally ruin the person in the process of doing so, doesn't really bother them. Not that they're sociopathic or cruel, they're just the conservative type of people who believe in that sort of stuff.
They tend to be Republican, and so somebody 'going their own way' too much is annoying for them. They're the type of people that get really seriously offended and upset at Hollywood, for example.
They like to have strong conversations about objective humanitarian principals. Subjective emotional moral values, they're not concerned with much at all. And that's the primary clash between Beta and Delta. Both groups find each other so morally off putting because the Beta is ignoring the objective morals for the individual, and the Delta is ignoring the individual person's emotions for the 'greater good.'