Earlier quoted context omitted.
The three big BSDs aren't exactly obscure, they might not have the highest server market share compared to windows and linux but they are the next on the list and often a primary choice for a variety of companies critical infrastructure, the most commonly sighted example these days is netflix. I think the outrage is justified.
Don't mistake this as OpenBSD's concern for all BSD's. This is just OpenBSD rant because they isolated themselves by not respecting embargoes in the past. Some ARM CPU's are also vulnerable by the way.
...I've no idea what your ARM comment has to do with it though. Meltdown is Intel specific.
A relevant question however might be who coordinated the work between june 2017 and now for Meltdown mitigations? Project zero at google discovered it, but did they hand over the responsibility to Intel or decide who else to inform themselves?