I think such questions are inappropriate on Ask Ubuntu because it is specific modem companies responsibility to provide appropriate drivers for their hardware.There is hardly anything Ubuntu can do for this.
Do you know that most of the drivers for Linux wasn't made by the hardware manufacturer but was coded by someone from the open-source community? That the hardware manufacturer doesn't support Linux it doesn't mean that we shouldn't use their hardware on Linux, so questions about hardwares without official Linux support doesn't make the question invalid. Having no support for a hardware is not a bug, but a missing feature.
Also that the modem doesn't connect doesn't necessarily mean that it is a problem with the driver. There are quite a few other reasons for such problems.
In general you should only flag such a question if it has other problems which should be flagged. If you don't like such questions just downvote them, but not flag.