Honestly, given the forums are a minority of a minority of the playerbase who nevertheless have extremely strong opinions on how the game should be designed, the only real answer to this debate is a data-driven one. Not an in-game poll or anything like that, since people constantly monkey's paw themselves in game dev votes.
You want to know much do people actually like this mechanic? How many people find it engaging?
Every transfer is a transaction on the database, so it'll be in the server logs.
What fdev need to so is look up every time a ship or module has been transferred in whatever timeframe they feel like covering, how long the transfer took, and the player in question's activity in that frame.
Find out what percentage of those transfers had the player still logged in when the transfer completed. What percentage of those had the player actually do something in-game in the meantime. Is there a hard correlation between those answers and the transfer times? Do people outside of these forums actually routinely keep playing while they wait for their stuff to transfer, or do they just go AFK or log out?
Make the decision based on that, not whoever's loudest in some forum argument.
It bears mentioning though... even those figures will be biased... how much use of ship transfers is simply because it exists? As an example, i never wanted Odyssey, and thought it was a bad idea. I still stand by that today,
even though i play Odyssey content and enjoy it.
A car business shouldn't open a side gig in selling mints simply because their customers almost always accept a mint when offered for free.
I use ship transfers simply because it exists. In many games, i won't use fast travel options as a general means of moving about, because there's side quests and other activities to be had along the way which make it worthwhile.
This is not the case with Elite... uss are not worth the effort, missions are tethered to docking at stations at start and finish, and the supercruise/ travel considerations as far as environmental or other hazards are virtually non- existent.
Ship transfers are, imo, tacit acknowledgement that as far as FD is concerned, the journey doesn't matter, and that's the bigger problem for ED, a game about the exploring a very large universe, than whether or not ship transfers are instantaneous.