I think it's just the dynamics of getting started with nitro that make people struggle with them a - a brand new engine is especially hard to start, so your first time may very well involve dozens of difficult pulls without it starting, maybe even breaking the string from being too rough or pulling it out too far. Once you've got it broken in, it should be nearly as easy to start as a lawnmower.
Pull starts are the most common option on RTR and entry-level-vehicles, so basically everyone's first experience starting a nitro engine is with a pull start, and then they upgrade to a roto-start, bump box, or electric starter, and only remember pull starts as the one that gave them a hard time. I've broken a few and replaced them, but only early in my nitro career, and they've lasted much longer since.