If you abstract it to the points of "something happens to slap you on the wrist lightly", then yes, this is true - but that's looking at it from a sort of lowest common denominator perspective. The difference between your regular death slapping you on the wrist and my death slapping you on the wrist is, in practice, fairly significant.
I would also contend that having your gameplay hindered for a duration which correlates with your misbehaviour is not all that light a punishment.
But compared to your entire character deleted, whether it be 10 hours of gameplay or 10 months, makes it very minor.
Plus, you're not hindering gameplay, you're just moving the gameplay to another location. Or else you're pausing the gameplay, during which time I'll do something else.
It's much
closer to regular death in games than to permadeath.
Since permadeath only has two parts to it: 1) You die, 2) It's permanent
Regular death has these parts: 1) You die, 2) It's not permanent, 3) You suffer some kind of setback
Your death: 1) You die, 2) It's not permanent, 3) You suffer some kind of setback
The 'intensity' of the setback doesn't make your death any closer to permadeath. It's a different concept.
Many games also have intense setbacks of various kinds: Losing all your items temporarily, one or more of your items permanently getting deleted, getting deleveled permanently, getting de-buffed temporarily, losing half your wealth (I found this common in older single-player RPGs).
You're just changing the intensity - but not near as much as permadeath.
"How can I make death carry
real weight to the player? How can I make it
actually be something feared and carry
real cost?"
"How about permadeath?"
"Well, uh, um, no, not
that much cost. Just sort-of pretend cost that they can recover from through more gameplay or through the passage of time. Just fake cost."
You want to make it actually impactful and costly, but not enough that they stop playing your game, so you shy away from the only real cost: Permanently taking away of something that the player has achieved, with zero chance of getting it back (except through regaining it the way they originally got it, thus having to redo what was already done).
The only real scale of legitimate intensity of loss through death, is how much is
permanently taken away from you. Anything else is an annoying inconvenience, or even an enjoyable diversion, but not a loss or suffering. It carries annoyance, not weight.
Your suggestion, while fine, adds gameplay, but not loss.
What's more impactful: Being teleported to some 'hell' level and having to spend time to get out, or having your favorite item permanently destroyed.
Some ideas to have real cost (as opposed to fake punishment):
1) Automaticly mark their currently active quests as 'Failed'.
2) Take away some or all of their wealth.
3) Take away their social ranking.
4) Take away some of their stat points.
5) Delete one or more of their items randomly on death.
6) Delete one of the user's skills.
7) Delete the character.
Teleporting me to a dungeon with a different texture on the walls is nothing. For some players, it's annoying, for others it's fun, for nobody at all is it costly.
The only 'cost' you are incurring is time, and irritation. Irritation isn't loss. Death in real life is feared because of loss, not because of irritation or time costs.
Your idea is fine as far as ideas go, but it can't really truly honestly be compared to permadeath in any way. It can't even be called 'costlydeath'. It's 'temporary-annoyance-death' at best.
And hey, if that's what you want in your game, and that's how your game works, that's fine! I'm not arguing for or against costs when players die - it depends on the game. I'm only arguing that this idea isn't related to permadeath, as it isn't permanent, and carries nowhere near the same cost.
As the designer for your game, don't delude yourself into thinking you are doing something that you're actually not. Don't let yourself rationalize or argue to yourself that your idea carries cost to players, because you wont be able to argue or rationalize with the players themselves that they should feel punished by it when they experience it.