Opinions become facts if you get more than a couple of people to agree with you.
Its not surprising that MPers want to balance the game for MP.
Its also not surprising that they fail to consider Solo gamers.
To get really involved in the MP games, you have to join the forum. But to Solo play its not such a necessity. You can lurk, and search, for a long time. The sales numbers, and the numbers of forum visitors that are registered vs unregistered tends to show how the numbers really compare. But in the forums its easy to get the impression that the game is mostly MPers of a certain type. If you hang around the other forums, or the IRC channel, you get another impression of a different grouping.
Unfortunately, altho the soloists are probably the majority, they will always be the minority in discussions.