I think it's a psychology thing. It still sounds expensive compared to the usual cost.
I also know that logically I won't really notice or remember how much I spent on teleports, but it still makes me cringe.
My immediate reaction was "I thought it already did that?" so I went investigating. ARR areas are very hub-based and only the most remote outposts won't give you a direct trip back to the capital city. (Limsa has so many options that it apparently overloaded the list - usually the same paths are available in both directions, but Costa del Sol isn't available. You can get back to Limsa by porter, but you can't go there. (It does have the ferry though, which is quicker.)
Expansion zones - both the routes and the actual maps - are more linear, and you can generally only travel within the map or to the 'next' location. eg. All stops in the Fringes and Peaks are linked to Rhalgr's Reach, then from the two towns in the Peaks you can travel to Porta Praetoria, then a single route from there to Ala Mhigo.
The porter prices are also more expensive in the expansion areas, so you don't get as much value out of it.
Im fine with the distance-based pricing - to be exact, it's a fixed fee of 100 gil plus the "price per malm" distance fee, with the 999-gil cap applied after adding them together but before calculating reduced prices for favored destinations or FC discounts.
It could be possible to make the fixed part of the fee variable (count down from 100 every X seconds perhaps) but the distance between continents would mean it's unlikely to be cheaper in the end.
And regardless of Return, I do feel like it should be cheaper to teleport directly from an aetheryte. You can use the smaller city aetherytes free of charge, so in theory it should be the same on a larger scale.
Perhaps in that case they could keep the fixed fee (since they're still charging you to use the system) but the travel cost could be halved.
There are definitely a lot of dungeons with one-way movement that require Return if you want to go back and explore, or get a missed treasure chest.
It's not free, but it's only 25% of the standard price.
In-universe, you're still using the Aethernet's system to travel there, so you still have to pay them for using it. (And actually, having put it that way, it's possibly quite generous for them to charge you less, rather than more, to get to a non-standard location!)