More digestion of the Conservatives purposeful "framing" of the next election- a majority or a coalition. While I believe some of the arguments have merit, I also think the main impetus for this "stark contrast" presentation isn't really addressed.
I think the main reasoning, behind the "stark choice" theme, is primarily a self interest consideration. The next election will be Stephen Harper's fourth as leader of the Conservatives. Harper has kept the conservative coalition together, no surprise, power tends to bind like glue. However, should Harper fail to get a majority in the next election, the obvious questioning of his leadership will begin, people will ponder the post-Harper era, wonder why he can't get over the hump.
Odds are higher that the Conservatives will receive less seats than more in the next election. Any result that brings a more fragile minority, the clock starts ticking on Harper, questions are raised. In reality, this next election is make it or break it for Harper. Should the government receive a slightly smaller mandate, Harper is weakened, people will openly wonder if he packs it in. In addition, you can expect the fully united Conservative coalition to fracture, as pretenders jockey for position.
I understand that the Conservatives see the "coalition" as a divisive issue that works in their favour. The highest polling the Conservatives have seen occurred during the coalition threat; they've never achieved anything close prior or before. For that reason, you can see why majority dreaming Conservatives want to re-create that formula. That said, underneath this motivation is a very simple calculation for Harper- it's now or never, do it or be doomed. Even if the Conservatives were to win the next election, should it be a smaller caucus, there will invariably be a "dame luck" feel to Harper. Of that, I have no doubt, and this consideration is part of the "stark contrast" rationale.