I've read back through the posts on this subject and it seems to me it has brought up a few good points.
Everyone here agrees that proper deicing is essential. The disagreement appears to be in the perceptions of those watching others operate in different ways than what they feel is safe. What we all have to remember is that we don't have the full picture when it comes to the operation of someone elses aircraft. As an example , I would bet that many were not aware that WestJet is able to depart with fuel frost within certain prescibed limits. Another example could be the letter that started this refered to one Westjet aircraft heading to deice while the other didn't. How in the world could the author know whether the non deiced aircraft hadn't just got in from a redeye and a quick turn precluded the need for a spray. I could cite many times that I have seen other airliners not spraying while I headed to the deice facility and only can say there are many reasons that could explain their decisions.
It is interesting that deice05 has not responded to any of these posts. I'm hoping that it is because he did what he should have in the first place and contacted the appropriate people at WestJet and voiced his concerns with them.