So the one of the main features of improving skills in tes was an incredibly reasonable,logical and fitting idea:
Practicing that skill makes it better. As far as stupid gimmicks go, this was the best [censored] one. It made perfect sense. It was complex and yet so so simple. Even if it were rediculously complicated and there were 500 skills for each individual thing, It'd still make sense, because all you'd do is do what you want to do to be good at it.
Come skyrim and skills barely affect anything at all. The numerical value gets higher, but we hardly/don't get better. Instead, We'd get a single point when we level up for a part in the skill tree. This was a massive downgrade. It was Unreasonable, Illogical and a totaly unfitting idea.
1. The system is now complex, because you need to navigate a tech tree. You've got to find out what's available before you start giving out your points, and need spend for things you don't want to get things you do.
2. The system is now more unnatural, because you don't go up incrementally each level, you have these huge leaps after tens of skill levels. You'd be at 0%,0%,0%,0%,0% , 20%, 20%...
3. You'd get splits. There'd be points where you've gone up ten levels in one thing and ten in another, yet when you level up you can only choose one to improve. The other one has to wait, even when you bring it up another 10, and maybe another, because there are more pressing perks to get. Ultimately you can get a hundred in a skill and not have improved it at all.
4. You get huge points of change; Aha, I've made enough iron daggers, I guess this means I can make dwarven now? Or 'aha, i've reached this level in sneak, now anyone I poke whilst sneaking dies. Granted, we kind of had this in oblivion, and it wasn't fantastic there either, but oblivion did have the advantage of the milestone perks being certain unlocks, as opposed to things you had to buy.