The fact that they were the first to support an infant OS that will end up powering the majority of the server out there is a stronger reason imo, but you're right, it's definitely a reason. Another one is the internet bubble of course.
IIRC they weren't the first (Caldera...?), but they were among the few that managed to survive the dot-bust. One reason they survived was that they were (then) charging less aggressively than others, at a time when money dried up everywhere. When the bloodbath was over, only them and SuSE were left standing; and SuSE was eventually swallowed and mismanaged by Novell.