That's only my impression and I don't claim authority on the subject, so I could well be wrong. I'm trying not to speculate on potential causes should my impression prove accurate. I don't want to criticize scientists on the one hand for pressing radical revisions of conventional wisdom to gain a reputation by proving exotic dark matter exists, and on the other for supporting dark matter solely because it's the current conventional wisdom.

It can take time, but doesn't have to take much; the neutrinos discovery took 25 years after postulation, but the quark only took four. But what I meant by the reference to neutrinos is that it's one thing to find a single predicted subatomic particle whose unique properties make it unaffected by electromagnetism and quite another to posit a whole new class of matter composing macroscopic objects five times the mass of normal matter. I'm not saying it doesn't exist or shouldn't be researched, I just don't want to rush to definitively say it does exist.

I agree that most matter meets the broad definition of dark matter; in a sense, that's my point: If we're simply talking about non-emitting non-relective normal matter, matter we can see is probably more rare than normal matter we can't, which is to say, neither of them is very exotic at all. Ultimately that was my real point in commenting initially: "Dark matter" is a phrase whose meaning seems to vary with whom you ask, and the evidence for the exotic variety is still inconclusive, so I don't want to count my chickens before they're hatched. I'm probably a little biased in favor of dark matter being a particular type of normal matter because I perceive a bias the other way.