There's also outside support due to converging interests. If DM is a particle that gives particle physicists an excuse to fund numerous experiments in an attempt to detect it. There are just more physicists motivated overall to prefer particle DM.

It's also safe. There is no reputational risk because "everyone" (who matters to you professionally) already agrees with you. There isn't much immediate upside to sticking your neck out. Especially in the era of social media.