You do realize that something like 60-70% of the worlds in the OTU are tech level 9 or less, right?
And to paraphrase Sam Kinison "We have deserts in America, we just don't live in them."
Low tech worlds are more often that not, pawns in a greater scheme in "typical" Traveller games.
What's in a label?
If a group of friends want to use the rules they're familiar with to play a PA game, who's to argue?
As Fusor suggests, it's no different in principle from any other dirtside game on a low tech, backwater world away from outside help.
Labels are used to communicate broader topics.
If someone said to me "Hey do you want to play Traveller" and when I showed up he handed me a Player Card with:
Name: Tug
999532 Stick-1 Hunting-1 Fire-1
"You're on a TL0 planet, not that you have any inkling of what TL means, and winter is coming in. You have a cougar pelt, a sharp stick, and a rock. Todays adventure is trying to find a piece of flint."
or:
Name: Edgar
665A95 Accounting-1 Calculator-1
"It's 1947, you're an Accounting Intern in Massachusetts, at an Accounting Camp for a New York based accounting firm. Here, to prepare you for corporate audits, your primary task for the summer is adding up the phone numbers out of pages in the the phonebook assigned by your instructor. He happens to have all 4 columns of 100 pages totals memorized and walks around with a riding crop. If you pass camp, you get to look forward to a 20 year career with the firm, eventually ending back here telling students to add up phonebook pages. Roll 8+ to add up page 27, column 3 correctly."
I dare say I would mention that this isn't quite what I was expecting.
Yes, it CAN be done. You'll note on the "How do you describe Traveller" thread, that most of those posts don't mention these scenarios. They mention stuff a bit more sci-fi. A bit higher tech.
When someone says "Hey, do you want to play D&D" and all you turn out to be a Level 1 proprietor of a candle shop, doesn't quite fit the label of what "D&D" is, does it? Wrapping candles and haggling with the tallow supplier. Doesn't quite fit the expectations you might have had going in.
Go in to an American bar, and order "a beer, whatever you have on draft" and end up with warm Guinness, most consumers will be disappointed.
Labels bring assumptions, that's part of their meta nature.
So, yea, it may use Traveller mechanics, square dice and index cards, but it doesn't sound like "Traveller" to me. That's not what it says on the box.