My personal view here is that the main problem is that many people are not very confident when it comes to cont. rwy calculations or adverse wx ops in general. I mean, how can you ask a question like " May I ask why you would want to take off from a contaminated runway?" How do you think aviation works north of 60 degrees latitude? It may take you an extra five minutes looking up the details in the manuals, and I have come across alot of captains who try to expedite the process by trying to "simplify" the situation based on previous experience. But the tables are there for a reason, to give us specific limitations and also to guide us. Of course there are cases where the only sane option is not to operate, like the V1 limited by Vmcg thing, but come on....3mm of slush/standing water on a 10000ft rwy is not necessarily a dangerous thing...if you open up the tables and get the correct figures.