No, it's more about the lack of 4G. Streaming full-screen HD videos and playing games on a laptop over 3G is a stretch, but I have no issues doing either with the 4G connection of my Galaxy Nexus. Even loading large web pages was noticeably slower using the 3G connection of my previous Droid.
Verizon's 4G definitely rivals Comcast's cable in terms of latency and reliability, if not in raw speed.