The writer's strike is no excuse. They made a conscious decision to keep Sylar in every season and turned him into a terrible character. The writers retconned the first season, couldn't decide if he was good, bad or misunderstood, made up new and more ridiculous powers for him, took them away, gave them back, gave him a love interest etc. Heroes made Sylar the focus and then wrapped every story around him like a daytime soap.
The Sylar Show was one of the many things that sent Heroes spiralling and him not being in this uneccesary reboot is probably the only thing that makes it worthwhile.