Oil Change frequency – What?

I’m a total newb to sport quads, having just procured a 400ex and 450R (long story). Anyway, I’m reading through the manuals and then checking online about oil changes and I see a huge discrepancy.

My 450R manual say to replace the oil and tranny fluid (it’s an ’05) – "Every 100 hours or 600 miles".

The rest of the internet seems to say things like "I replace mine after every ride", or "after 10 hours", or "after every couple of rides".

Is Honda way off, and it’s really too long to go the recommended "100 hours"? Oil is cheap, and dead easy to change. So I’m not worried about that. Just wondering why the huge discrepancy. ??