What is serious Judaism?

At Ohalah this week, Sid Shwartz reiterated what Larry Kushner said 40 years ago in an article about "tent peg judaism," namely that synagogues must focus on serious Jewish content. We should not be JCC's, focusing on social content, but rather should become places that encourage serious Judaism, i.e. torah (study), avodah (prayer), and gemilut hasadim (acts of lovingkindness).
I was struck by this dichotomy between serious judaism and empty judaism, and think it is problematic. Too often, people think "serious judaism" means praying in hebrew, or studying Talmud, or other things that all so many contemporary Jews have no interest in. So when those "assimilated" masses don't come, we can say they are not serious Jews; I had a congregant say that young families don't come to minyan because they are "not spiritual."
The fact is, there is a very important middle ground between what looks like "serious judaism" and empty Jewish socializing. I know families who identify as secular and have no interest in "Hebrew School," but if you tell them about a Jewish Drama club which teaches values through improv and theatre games, they are in. I have a friend who is leading a Tuesday night get together with some study, some reflection on what they are grateful for, and a shema meditation; he is hoping to get people coming who don't come for a "service." I know families who will come out on a Friday night for a shabbat singalong and potluck, who would never come to a kabbalat shabbat service. These aren't just gateway programs; they are significant ways to enrich the spiritual lives of Jews.
We need a language for the middle ground between "serious judaism" and "social club judaism." These kinds of programs: fun, accessible, meaningful, joyous, are seriously Jewish. They are not serious, and that makes them work. The fact is, many of the people who identify as secular do yearn for community, for meaning, for children with good values; they just don't associate that with religion. We need to start giving them something seriously meaningful, seriously joyful, seriously transformative. Let's get serious about this.