a) it was unreliable and dependent on system load and you never know what load the system will be carrying, and
b) frame rate was easily controlled using fewer resources, left control in the players domain and gives better playback.
This is why I am a huge Quicktime fan. Quicktime delivers all the time every time.
Fast forward to today. Many professionals still have not figured this out. Witness: above link to Verizon Broadband Beat. Hah! They think they can't support Mac because they won't get into Quicktime. News flash from the past: Quicktime is a quick download and simple install on a PC and guess what? It works all the time every time. And it won't eat up system resources like that no account Windows Media crap (which, by the way, does work on Mac just as good as it does on a PC) and it won't invade like Real (which also works on Mac just as good as it does on a PC). So wize up you geeks. It's 2006. I've know this for 10 (count them) years. What's taking you all so long?
Oh, and guess what Verizon? You do support Mac.