That is a raging debate (has been forever) and I think there is no solid answer. Everyone has their opinions, here are mine:

1. Honda engineers have a reason for recommending 30 PSI. I do not know for sure what that is, but it's probably the best "compromise" for merging traction, tire longevity, and safety.
2. Higher PSI will affect traction to a degree, and will affect tire wear to a degree. Personally, living in Phoenix AZ (home of 320+ days of Sun) I am not concerned with traction problems. I do not drive my HCH like a sports car, and wet weather rarely affects us at all. Tire wear is not that much of a problem if I rotate the tires enough and these tires are pretty cheap to replace (at $65 each) if the wear is uneven enough to make me replace the tire after 30 to 40 thousand miles.
3. The main thing I have to worry about in overfilling tires is HEAT. It gets HOT in Phoenix, and if I over-inflate to say 40 PSI on a tire rated at 44 PSI max, the heat expansion will take that PSI up over 50 on the hottest days if I have driven on the highway for a few miles - I saw that last year in August. So I need to be careful in Summer to keep it about 35-38. I have braved 40 PSI this Winter and have seen no problems.
4. I inflated down to 32 PSI on my recent trip to Texas, where I knew I had a loaded car and would be driving in snow/rain/ice on occasion. I sacrificed max MPG for max safety.

So each person should consider their own circumstances and base their PSI on how their life is. I can generally over inflate a little in the Winter and I have to be more careful in the Summer.