I think that their (I mean Jewish liberals in general, since I don't know your friends) underlying leftist philosophy disapproves of wealth on principle, since it doesn't reconcile with "equality" and since the Left seems to assume that the "wealthy" got that way by "exploiting" the poor. The fact that wealth building actually is of tremendous benefit to all of society is at least irrelevant to leftist philosophy.
It's true that many "liberal" Jews are compassionate and really care about the disadvantaged, and are willing to devote both time and money to worthy causes. What bothers me is that all this "social action," admirable though it may be, is always framed by leftist philosophy.
I guess I'm not a good temple member, because through all these years of belonging (and sending the kids through Hebrew School, I hate to think what they were taught, as the "Education Director" was recently telling me how great socialism is)I've been oblivious to the very active leftist politics pursued by Reform Judaism.
Now that I'm aware of what's going on, and it's becoming obvious even to a "2 day a year" member like me, I am considering resigning my membership. This really causes me great anguish, and my wife even more.
Where do you live? If in LA, you could check my temple out.