This is why I've mostly stopped using it. I dislike the way that it has that ugly yellow tint applied to the background when you're in the menu, I dislike how textures animate when the game is paused, I dislike how it has those horrid looking decals built in, I dislike how the projectiles have additive transparency instead of normal transparency like Boom uses, I dislike the "secret revealed" message and sound, and I dislike how enemy item drops fly upward by default. I don't mind the features described existing, and I know they can be turned off and disabled quite easily due to user preference, but it bugs me how all of these changes are just automatically applied to the base game. This stuff should be left to mods, and if such content is deemed to be "defacto base", it should be a seperate, optional pack, similar to skulltag_actors.pk3 or something along those lines.
ZDoom being filled with arbitrary design choices
Despite the very negative tone above, I'm not trying to say any source port is better or worse than others, I'm just stating my own personal preferences and reasons for migrating to other ports. ZDoom's still a pretty good engine for what it is, it clearly has a lot of work put into it, it's just that it has so many arbitrary design choices and changes that it's too far from my personal preferences to like all that much in the context of playing Doom engine games as-is, or even simple, non-elaborate mods.
It's a great engine for TCs, but if you're going the TC route, I prefer to have many subtle things changed for the sake of tweaking a custom overall feel to perfection, rather than work within the limits of the "Doom feel". Nash has been kind enough to let me test his custom build and some content he's made for it, and I love all of the subtle changes, like making the pixels square, making the movement less slippery, adding Quake-like stuff such as view tilting when the player strafes, and weapon "drag" where it tries to recenter itself when you turn, as well as moving the weapon forward when you look down and backward when you look up.