Most problematic spells that have been with the game for a long time seem follow this particular trend that they only become problematic when they become easier to cast.
Light was once a 1st-level spell. Rarely used.
Goodberry has been a Druid spell for decades, but it always had this opportunity cost where you'd have to specifically go out of your way to have it, at the expense of other spells. 5e lets you prepare it and if you don't need it, you can use the spell slot for other things.
Create water has a similar history. I remember Dark Sun going out of it's way to nerf it because it would wreck the setting (which make sense), but at the time, I don't think I ever saw it used. Once 3e gave Clerics the ability to ditch needless spells for Cure spells, the opportunity cost went way down, much like Goodberry now.
Tiny Hut didn't really offer useful benefits for most situations in previous editions. Even when it was eventually powered up (I think in 4e), it wasn't used (mostly because Ritual casting was a pain in 4e, so only a few Rituals got much use). Ritual casting in 5e basically means it's a free spell that you don't even have to prepare, so it can get used more. If it cost you a Fireball, it probably wouldn't be used much.
Ultimately, camping in the wild is dangerous. Being interrupted by a night encounter used to be not only common, but the worst kind of encounter- if everybody takes a watch, there's the risk some not-so perceptive character will get ambushed. Then there's the inevitable checks to see who wakes up and can actually take part in the combat. Spellcasters won't have spell slots back, warriors might not have their armor- it's a real pain in the ass.
Things that mitigate this really should exist, one might say they need to in your typical D&D setting. But you run into this problem that if the spell can't actually prevent an ambush, then it's going to be used. So WotC said "hey, maybe it should prevent you from being snuck up on by Bugbears and strangled in your sleep, and give you time to respond". And that's great.
The problem is that it does more than that. I'm sure the anticipated play loop would be for the caster to immediately start casting spells, so the Hut would end on their turn. But like any open ended tool, somebody is going to find ways to use it outside of it's intended use.
Given the opportunity, gamers are going to game, and all that. "Hey, did you realize this thing is basically a level 3 Wall of Force that doesn't take a spell slot?"- yeah, someone is going to devote brain power to finding good uses for that.
Until it becomes a problem, however, it lurks unseen. If you don't routinely hit your players with ambushes for having the nerve to take long rests, or the players are just careful about where and when they rest, it's probably fine. Heck, even if all it does is prevent someone from dying in their sleep, also fine.
But when someone realizes it can be exploited, and lead to play patterns it wasn't intended to support, it is a big deal. You have to nerf it. Ban it. Have intelligent foes prepare for it's existence, despite the fact that it's not really something one should encounter super often in many games. It's like the time-honored chestnut of monsters dogpiling the healer, when in reality, most monsters don't use magical healing, and divine casters might not be all that super common. The game would become pretty lopsided if all enemies were ran as if they were ignorant of such things (though, amusingly, there are DM's who are happy to deny players such "basic information", lol).
I don't like that LTH can be a trap for the inexperienced, and that it can force a DM to worry about countermeasures for something that, realistically speaking, is a potent and sometimes vital exploration tool. In a world infested by dangerous monsters, you'd be foolish not to have some kind of portable fortification, be it an armored RV or a fortress in your pocket.
But ultimately, it's far from the only such thing in the game, and in the grand scheme of things, it's far from the worst thing players can do to warp the game with magic. One day, I might actually find myself in a high level game where I suddenly have to worry about things like Simulacrum, lol, and worries about LTH will seem like fond, nostalgic memories.
