Respawn Entertainment developer, Brent 'Scriptacus' McLeod, commented on an Apex Legends subreddit post about gun recoil patterns. Most of the comments were confused by the decisions made by Respawn, and even why they changed certain guns from Titanfall 2 to Apex Legends.
Scriptacus goes rather in-depth on multiple topics, giving fans a glimpse in the balancing process.
One of the comments asked why designers changed the nature of some weapons from TF2.
"TF2 recoil was functionally random. Each bullet fired applied a base amount of pitch and yaw, and put an extra amount randomness in any direction on top of that. This put a very wonky skill ceiling on controlling recoil because it was either easy to control (e.g. "up and to the right") or impossible to control; it was primarily dependent on the tuning of that extra randomness value. Yes, the Flatline had horizontal recoil, but it was also impossible to learn because the bouncing left/right were completely random," explained Scriptacus. "We did experiment with a more horizontal recoil for the Flatline in Apex, but when it comes down to it, trying to practice and learn a recoil pattern that involves rapid left/right direction changes isn't fun. It's hard enough to do with a mouse, and damned near impossible on a controller."
If you want to understand Respawn's philosophy on weapon recoil and gun balance, you should check out the rest of the responses by Scriptacus.