In the case of Sneak, by 30 skill it should be just about good enough to sneak up on some wildlife or a few of the less-observant NPCs with a "passable" success rate, and that's about where any "Thief" character is going to start at, unless they have a racial bonus to it, or didn't bother to take their intended skills at Majors (or even Minors). Speechcraft can be practiced "safely" by Admiring or Intimidating respawning Guards or other "generic" characters, rather than "named" characters who will carry that lowered dispostion for the rest of the game if you bungle it. As an Imperial race character with Speechcraft as a Majr skill, it can be "semi-useful" right out of the C&E office, but the chance of lowering the dispositon of a key chracter and having it haunt you later still makes it a bit "iffy". Again, it's not readily made clear to a new player what's "safe practice" and what's potentially a long-term problem.
Rather than increase the "tutorial" aspect of the game, or improve the manual, several of the "unintuitive" game mechanics were simply removed and replaced with......nothing. The others were changed into something with different problems. Some aspects improved while others got worse. Somehow I preferred a few of the earlier ones (but not all), but would have hoped for either some adjustments or corrections (some "polish") to the earlier mechanics or else a "better" design, not just a "different" flawed (and unpolished) one.
I've recently run a MW character who frequently used a Spear as a secondary weapon, although it started out at 5 skill, with no paid training. VERY effective; I can understand some of the balance issues that made Bethesda consider removing them, although I don't agree with the decision. Other characters have fought (successfully) with Misc. skill weapons, eventually becoming proficient with them. Another raised Enchanting from a Minor skill at 10 to 50+ by heavy use. My first character to finish the MQ relied heavily on the Sneak+Marksman combination, both starting out as Minors and eventually topping 90 skill in each before I intentionally started to work on other skills to avoid becoming "overpowered". If there's any problem with a Morrowind build being a "dead end", it's because you noticed the problem and quit, rather than continuing and fixing the problem over the next few levels. I agree that you can make a build that's not fun, but that's not a game mechanic issue, it's a personal preference which some other player will totally disagree with.