Varieties of criticism
Conservative criticism has nothing much to do with "left-wing" or "right-wing", because left-wing people are often very conservative, in the defined sense, while right-wing people can also be very radical, in the defined sense. The difference between "radical" and "conservative" has more to do with the belief in whether "a change to something genuinely new" is really possible and necessary. Radicals typically believe strongly that such change is highly desirable and necessary, and that it can be achieved. Their criticism is that there is "not enough" change. Conservative critics, by contrast, are very skeptical about any such change, because they feel the change is really "just another form" of something that already exists.
Belinda Stronach
Stronach was generally to the left of her Conservative caucus colleagues, supporting abortion rights, gun control and same-sex marriage. During her Conservative leadership campaign, she called for a free vote in parliament, with votes cast individually and not along party lines, on same-sex marriage. She spoke and voted in favour of same-sex marriage when the issue came before the House of Commons in 2005; a position she re-affirmed as a Liberal in 2006. Social conservative elements in Canada were critical of Stronach, calling her a "Red Tory". During Stronach's leadership campaign, REAL Women of Canada said: "If Ms. Stronach is elected as leader of the Conservative Party, social conservatives will no longer have a voice in Canada." Stronach, for her part, promised after the leadership race that she would do her best to keep the party from moving too far to the right. She cited discomfort with Stephen Harper and the Conservatives' policies as one of her reasons for crossing the floor.