"I don't understand why this board has, in the past few months, suddenly become populated with several "investors" who post constantly, who often make no sense, and who seem to come across as being quite uneducated"

Because they are fairly new to this forum (ex. Spot), while on the other hand many well known and respected members of this forum are not participating any more or gone away.

Gone away for lack of patience with the slow pace of progress.