As a TF vet, I feel you. Yet I still enjoy the game to this day due to how enjoyable it is from getting easy kills by using a Titan or depending on how good you are. Yet, here's some of my sample opinions with the game...
-melee system SUCKS! Either remove it from TF3, or fucking fix it. This has to be the most frustrating issue in my experience and i'm surprised you haven't really mentioned it. I even seen enemy player melee's not working on me and I yell "that was supposed to kill me!".
-SMG's are just OP. Barely no recoil and high TTK. Yet, I love them lol. They need a heavy nerf for TF3.
-Some gadgets like the turret or smart pistols are just OP. I find it funny how many bash on the SP, yet they usually use those pilot turrets themselves. So I just use the SP because why the fuck not.
-Personally, I really never looked deep into the maps. I really like how most of them are medium size and usually filled with action At least it's not COD level bad.
-No player kills AI's? Who the hecc you've been playing with? For me, killing AI's is a MUST! Maybe it's a PC thing? I see AI's getting killed EVERYWHERE.
-Surprise there's a big praise for PVP. Personally I hate it because that's where the sweaty players are usually mostly playing especially Twitch streamers. They just use the only top weapons (mostly SMG's), and bam there's getting nearly 30 kills per round. I rather deal with getting smushed by a Titan multiple times than sweaty SMG's players. Again, maybe it's just a PC thing. I've instantly noticed how on Xbox, more players uses that OP LMG (forgot what's it called) meanwhile on PC, no one uses it.. hahah.
As for the pilot vs titan combat, I understand that it's not for many especially my friends. Yet in my experience, I really had no issue with the combat since I know i'm able to get a chance to use my own titan and stack kills. Usually I meet up with good titan players and get killed a bunch of times while trying to kill them. Yet surprisingly, I find it fun to keep dying over and over just to get that titan kill and tons of EP for me to get many own titan. If you don't care about your KD, maybe you will have more fun.. and thank god it doesn't show your KD in matches. I have a feeling more players would avoid killing titans. Yet it's shocking how this is the ONLY game where I fine it fine to get killed multiple times because I know I will get a chance with my own Titan.
I still think Attrition is the best and most fun game mode in the game. It's what Titanfall is meant to be. As for PVP, again imo, it's just a COD like sweat match based in my experience.
Overall, I feel that Titanfall just isn't for everybody. There's a reason why it dropped from 20K players to just 2K in a few days after the Steam release lolololololol.