Somehow this continues to this day, even with the very latest versions, though now not usually at all close to the time of a version upgrade.
I've noticed that along with the spam Speeddials, Opera inexplicably disables extensions (at least it tells you that it's doing so now, which is probably why I'm noticing it).
I wonder if the two phenomenons are connected.
If so, maybe it's the spam Speeddials being injected that somehow causes Opera to want to disable extensions (that makes more sense than it being the other way around, at least).
That might make it a case of one hand of Opera (the one injecting SpeedDials) not communicating with the other hand of Opera (the one looking for suspicious events, and maybe disabling extensions when it thinks something is wrong)?