I, of course, didn't expect that of him; that's because he and the rest of them deny themselves a lot of happiness because they believe that taking an active pleasure in the things of this world is a sign that they're low, garish, slobby people wallowing in the muck. The wrong sort, you see, wear bright colors, talk far too much and get needlessly combative, eat threatening foodstuffs, paw all over one another, are too permissive with their children and dress garishly and lasciviously.
Speaking of Wilf and Mira, the bright colors and demonstrative nature of the Sobinskis are a threat to the way they see the world. After all, if it could be said that there's something to saying exactly what's on your mind to the people who bother you, taking an active interest into what your children do and thinking of their concerns as being meaningful, showing affection and not dressing so as to blend in with the crowd, that would mean that they'd wasted their lives in the pursuit of an empty comfort when real happiness was there all along.
This exaggerated need to not expose themselves to risk is why they seem to prefer dull, slug-like males and bovine females as mates; that way, big scary emotions and the bigger, scarier fear of disappointment can't threaten them. Better to not really live at all than to live with any sort of pain, you see.