But this is not a specific problem of rationalists..

Sport fans do have strong feelings while watching basketball and that's socially acceptable. As a result children want to go into the NFL instead of becoming scientists.

It's a broader problem with Western culture. Feeling strongly about things is not 'cool' or impressive.

Yes. That means that if you manage to have community where having strong positive feeling is the norm, all sorts of people should have an interest into joining that community. If you manage to succeed at that task you have a pretty big lever on your hand to produce large societal changes.

through its presentations in media, and also that I have a strong impression that most people have encountered enflamed evangelists

The problem with evangelism is that it's usually targeted at outsiders. Instead it's much better to target people who are receptive to your message and give them a narrative that allows them to feel more positive emotions by being part of your cause.

As your cause grows and people who are unhappy with their lives have a valid reason to come to your movement and believe your narrative to become happy. You don't go to them and force your narrative on them but you let them come to you.

If a journalist comes and wants an interview and you have 2-3 free hours you gives them his interview but you don't really need to go out and try to persuade outsiders. The most important work is getting the community itself right.