In general, it's filling the vacuum left by religion. One part of that is what you identified: people generally need something greater than themselves to identify with, and "intellectual" is a tempting option.
Another part of it is that people generally crave certainty and fear the unknown. Religion fills that need by providing crisp, clean answers that don't provide a lot of room for questions and "what if"s. In the absence of a traditional organized religion, people try to fill that void with what seems to be the new, popular replacement—science.
Unfortunately, science is by design all about uncertainty. As soon as it becomes a dogma it ceases to be science.