It's a game; everything is accessible and mastering a trade doesn't take an actual lifetime out of necessity. The key is if you're actually roleplaying you're not some person playing a game where you don't age and everything happens in accelerated time.
Your role is that of a warrior and your immediate concerns are your weapons and armor. You don't realize you can powerlevel enchanting to mastery in a day so it's not something you're concerned with.
This still does not mean that over the course of a "lifetime" of adventuring (this is highly abstract, as yes, the passage of time is simply poor when it comes to crafting), a warrior will not eventually come to practice alchemy, enchanting, and smithing.
My issue with what you're saying is that you are hindering a good half of what it means to be roleplaying with your message in this thread. You appear to be saying that people do not learn things over the course of their life. That characters remain static. I highly disagree with this notion. I find that it is a strong method of RP to show the minor shifts over time that eventually add up to create a character that may very well be unrecognizable from when they began.
I could begin play by joining the Legion, working as a hardened warrior. Upon winning the war, my character could become disillusioned with the Empire, join the Dark Brotherhood (being that this is not the spoiler board, cannot provide details as to why this matters, but I imagine most understand the issue with this idea), with a complete shift in skill focus over to the stealthier arts out of necessity for the type of work (or maintain the warrior style, as that still has a place in the DB).
What I disagree with, is some sort of notion that you're RPing better than I am just because you're imposing artificial restrictions on yourself for almost purely metagaming reasons (X is OP). Its the doctor with the horrible bedside manner "Doctor, it hurts when I do this with my arm!" "Then don't do that with your arm." That doesn't solve the problem, it merely buries it.
Yes, this will probably never be fixed. No, it is not acceptable to say "just don't do it." RP is not something as static as pick generic class X and stick with it, imposing artificial restrictions on yourself. All this means is that yes, Skyrim has flaws. And that's OK. The game is still amazingly fun. No, player made mods will not solve this problem, at least, not in an acceptable solution to me. I feel that the vanilla game is at core what needs to be balanced. Skyrim is basically a game where the GM can't tell the player "No, that's not going to work," or one that fails to cheat on that one roll in order to keep the game interesting. Its fun for the player for a time, but eventually breaks down.
Also, just saying that the other NPCs in the game don't smith/enchant/brew potions does not mean that inherently the PC cannot. The PC is Dovakhiin, they are unique, a prophesied individual who appears at the proper moment in history. They are beyond legend. So yes, it is acceptable that the PC become god-like, and that the PC is infinitely capable of learning anything they set their mind on. Or are you saying that "True RPers" also get to ignore exactly what occurs in the game (i.e. people that claim to say their character is
not Dovakhiin)? Gee, I wish I could tell my GM at the table what is and is not true in
their game world.
Part of RPing is working within the provided constraints (not doing so is to Mary Sue oneself, to god-RP). The issue here is that Skyrim does not provide the appropriate constraints to the appropriate skills. My recommendation is purely for the removal of the fortify crafting effects, as their synergy is the main problem. Each skill individually on its own is sufficiently powerful to justify itself. The synergy is what causes the heavy OPness.