On one level, it's evil lock-in. On another, it's all-products compatibility with very tight integration.
I don't like being locked into Apple, but I can't argue with the extraordinary convenience of doing it their way. New iPhone or iPad? Just set it next to your old one and it will pull everything over. New Mac? You can clone from a backup of a different Mac. I started with an iPad, got a Mac a few years later, and finally got an iPhone after Google released the amazing (loved the fingerprint reader on the back for unlocking) but disastrous (the battery would decide to go to hell one day, no warning, and you were losing 30+% of power per hour) Nexus 6P.
I don't like being locked into Apple, but I can't argue with the extraordinary convenience of doing it their way. New iPhone or iPad? Just set it next to your old one and it will pull everything over. New Mac? You can clone from a backup of a different Mac. I started with an iPad, got a Mac a few years later, and finally got an iPhone after Google released the amazing (loved the fingerprint reader on the back for unlocking) but disastrous (the battery would decide to go to hell one day, no warning, and you were losing 30+% of power per hour) Nexus 6P.