Teapot_There's so much I want to say but a lot of it just comes down to having very little experience of actually playing 6v6. It's not a criticism of your casting skills but your understanding of the game, for instance being surprised by and saying its creative to see a medic being body blocked in an uber exchange when it's a fairly common occurrence.
I also don't think it's fair to hide behind being a play-by-play caster, you're casting at the top level of the game with minimal knowledge of how the game is played. I appreciate the time you put in and your enthusiasm and willingness to accept criticism to improve as a caster but like I said, your actual casting skills are good but your understanding is what most people don't like about your casting.
From my perspective (someone that has somewhat called you out in the past I'm sure you recall) this post is entirely what I dislike when you cast. Your voice, charisma, ability to hype, play by play etc are all absolutely fine and some are even great. The issue for me (with any caster) is when a caster like yourself tries to say things that are on the edge of analysis.
Gecks seems to have grasped this really well and you never really hear him trying to analyse a situation. He always keeps it to the very basics in that regard and then immediately throws it to his co-caster who does the proper detailed analysis. It works best this way because no one wants to watch a stream and hear a guy get things completely wrong, act surprised when seeing very common things as if they are outstanding or unique plays (not hype, but just generally seeming clueless) or anything like that.
Stick to what you are good at and try to keep that stuff to a minimum and I for one will enjoy your casts. I had the same problem with Pledge when he used to cast forever ago. I considered him a pretty good play by play but every time he started to try to analyse anything I cringed and it kinda ruined the experience.
Good luck buddy.