That is an interesting point, I would say actually the opposite, that microsoft/blue fang did take into account that the game would be modded. The UI files are all just in a ztd like everything else. In fact, all the ztds are as you know are only zip files, meaning anyone can look in them pretty easy. They did that on purpose. In fact if anyone were to decide to make the bigger menus mod for 800x600 they could do it too, I'm not holding some secret in a bag here. This all happened for me by accident, I just was looking through the UI layouts and went, hmmm... I wonder... and then suddenly bigger menus was born. But the part that takes the time isn't just a simple code change, I had to redo all the UI artwork to fit the bigger menus.
But getting back to the thing about hacks... part of the fun of the zoo tycoon modding community is that everyone works very hard to make all the mods work together and I want to do the same, but... if I were to never touch certain files because someone else already made a hack that uses that file, then that puts a limit on what you can do. Bigger menus would never exist because it does interfere with Jay's purchase baby mod. So while I can appreciate that the mods should all work together if possible, I'm not looking at that as a line that can't be crossed to make a better game. If you had to make a choice between bigger menus, and a purchase baby mod, that would not be the end of the world! (Thankfully though Jay told me I should try to integrate his mod with mine, hopefully he still feels that way, so that I can make a version of bigger menus that makes everyone happy in the end, which is a lot more work than just making one mod for everyone, but still I am willing to do it, if that's what people want.)
Also, in the zt world bigger menus is known as a 'hack' but in most mod communities it would simply be a 'mod', and conflicts with other mods wouldn't even be mentioned. Typically like for skyrim or battlefield or wow or other heavily modded games, when conflicts occur, people just tell you to delete all your mods, add them in one at a time, and then... you'll know which ones conflict with eachother. Some games even have tools that can go through your mod folder and tell you which mods conflict, but, that doesn't stop people from making mods that conflict. And the larger or more comprehensive a mod is the more likely it is to conflict. So in other words if I were to make an expansion that changed the UI, the R&D, the economy, the AI of the game, the Staff, the whatever else, and then released it, at the end of the day, you could either say, no way i'm not playing it, or you could play it. It is a choice, no one is forcing that. Just like when Blue Fang made MM and DD (actually just mods in a way) it broke so many of the user mods. But who in their right mind would say, I don't want MM and DD because I'd rather keep my old mods...
Anyways sorry for going off topic a little, just some food for thought. In my mind, Blue Fang was very much aware of what they were doing, and this game (zt1) was way ahead of the times.
A little quote from a skyrim tutorial on solving mod conflicts:
"Going crazy with mod installations, as we did in our previous Skyrim Overhaul kit, can lead to constant CTDs, freezing, black screens, glitches, and crashing; despite how fun running through every possible solution in a crash fix guide is, it's not fun at all to potentially wipe your Skyrim installation clean and remove all mods. Having installed well over 100 mods myself (with many, sadly, being removed), I've now tested a variety of methods to troubleshoot mods in Skyrim. Let's run through the troubleshooting techniques so you can find the conflicting mods in your TES installation! "