I saw people on Reddit suggesting that as well and I've thought about it and I don't really see the benefit in it. If it were actually done, yeah, there would be a few nifty things about it, but... well, it would be a lot of work for little payoff, and there are a lot of complications.
So, first of all, you can't just copy all the files from one game to another. You can do that with some of them - all the items, characters, and placeables should be fine once the assets are ported and dialog.tlk adjusted. The module files can be copied over without much change, but the area models need to be converted and that's a bit of work. It may take some time, but that's something I could see happening and I'm planning to do some myself. Nothing ridiculous so far.
Now, here's the problem. All of the audio is set up differently in K2. It's not a difference in format, but the file structure is different. In a worst case scenario, that means every single voice file has to be renamed and relocated in order to work in K2 and then every single dialogue file edited to account for the new VO file names. That's hundreds and hundreds of files.
Additionally, K2's NWScript functions are changed from K1. K1 scripts might not necessarily execute properly in K2. Some of them will, to be sure, but I'd be surprised if there were no problems at all. You'd be looking at the same level of bug fixes that the restoration projects have faced - and we're still fixing bugs that even those didn't catch. Furthermore, we don't have access to all the source scripts, so some things that go wrong would have to be programmed from scratch unless a more reliable script decompiler were developed.
When you add all those up, this would be the largest KOTOR mod ever attempted. Easily bigger than TSLRCM or any planet mod. About as much work as a total conversion mod and how many of those have you seen released?
And as much as I'd like having access to K2's new script function and assets and all that good stuff for K1, I'm having trouble seeing the point of it all. I can think of some things that would be nice to have, but I don't know if they would really positively impact the gameplay. Some would be tricky to implement too. It depends on what specifically you want to apply to K1, though, and I'd be interested to hear what people are looking for.
Take the prestige classes, for example. There's no way to utilize those in K1. The player can only have two character classes, so unless you change the game to start as a Jedi then that's not going to work. Maybe you could give them to the party members or maybe you could edit the feat gain so the regular classes get those things at high level. You also wouldn't have all six to work with anyway; I think half of them would have to be converted to Jedi classes. It's been a while since I looked at that, but I recall that the starting classes can't be changed and they're Jedi classes in K2 - so you'd have to un-Jedi those classes, but you can't add more Jedi classes, so there go half the prestige ones.
And about the level - well, K2 doesn't have a level cap. You gotta work out what to do with that. Either by leaving it alone and just allowing some minor level gain after the Leviathan or Lehon or wherever you hit level 20, or adjusting the XP gain to allow for higher levels than normal.
The enemies also scale by the player's level in K2, so you would have to work out how that would affect things and re-balance the difficulty of all the encounters. And you'd have to take into consideration the new Force powers and feats now available from K2, and the different upgrade system. A lot of playtesting would be required.
The saber forms are another mechanic that would have to be tested a lot - and you'd have to figure out how to incorporate them into the game. Perhaps Vrook's lines from K2 could be reused and you could go see him after finding each Star Map?
I've thought of adding an influence system to K1 - it could be done even without the port - but for it to have any impact on the game would require a lot of programming changes.
There are a lot of potential improvements here, no doubt. There's a reason there have been a few lightsaber form and Force power mods and the like to mimic what was introduced in K2. But even if you managed to port the whole game to K1 and had access to the real thing, you'd still have a lot more work to do to make it count for something. The mechanics are done for you but that's not really the hard part - the hard part is the execution and you'd have to repeat what a number of mods have already done.
Anyway, I'm not knocking the idea. I'd be very interested to see what one would do with it. But I'm not interested in that one being me. I'd rather spend all that effort on making new things.