Having gone through undergraduate at one of the only two schools that use that grading system I am quite familiar with the interpretation of the marks, and trust me schools don't "round up" to a B, a 2.7 is a C+, in the same way a 3.9 is a B+. The conversion on this chart is a bit strange as you generally use a GPA at those schools out of 4.5. A+ = 4.5, A = 4.0, B+ = 3.5 B = 3.0, C+ = 2.5, etc.
This clarification is even more important for most graduate students who are applying with a GPA between 3.5-4.0, even though often your percentage marks coming out of courses could be mid 80's you CGPA could be say, 3.7 which is ineligible for federal funding (NSERC, etc). While other schools that use a % based system will be eligible with identical marks.
Anyways, long and the short of it, as much as I would love them to "round up", this is simply not the case, a 2.7 is a C+, and you won't get into grad school with it (while at a 3.0 you might). Also, a 2.3 would be considered a C not a C+.