It would certainly make people think twice about their comments, and put more effort into them.

However, while it certainly wouldn't do you any harm, and me very little harm if the dust threshold was increased, it would damage new users more, so it's a good idea, but a difficult thing to balance.

A sensible approach to implementing any increase would thus be to do it very gradually - raise the threshold to 0.05 for example, see what happens for a month, then up it from there if necessary.