I think there are currently 3 reasons why most parsec ships are left in the hangars to collect dust mountains but keep in mind that this is MY personl opinion of reason.
1st: The Look Design is nothing special
The look/design for most parsecs is nothing really special or just bulky (Domi and Const) + they have those scratches that you can see if you zoom in close (yes this is what anoys me on most ships that are non Siri/TC... scratches on the hull
)
If i alone take the RDX ships as comparision they have an much better design AND no scratches at their hulls
. The only exception i fly as Parsec is the Hunter simply due it has from all the ships the "best" design if it not has the Siri SB equiped (the Siri SB not really looks like a Sniper at all imo... more like pincers from a bug
)
2nd: The "base classes" have become obsolete since Hybrids have been introduced
Basicly since Siri Ships showed up the 1st time Parsec ships lost their Status due the bonus in armor was not more defining their "prestige" status due the combo of Siri Ships was simply better... for a long time the Myst was the top class for Siri along with the Punisher (from my knowledge the most used ships during the Siri time).
3rd: Pilots seem to ask more for RDX Event/Ships then for Parsec ships
As much as i´m aware to majority of Pilots seem to ask when the next RDX Event will happen (what normaly is every 6 months since the last RDX Event happened) and what new ship will come with this event. I think the issue here is that SSG is a bit "cornered" in this situation cus for one it´s "easier" to simply make another RDX Event with the same rules/mechanics then making a complete new Event for 1 new ship.
I must admit i don´t really remember how the Hunter could be obtained (it´s a few years since i got it
) and i only remember that for the Hyan we had an mission at Mars that had to be done a couple of times to provide the BPs for a full sq but not more in detail what the mission itself was.
So the question now is how could this be solved so that new Parsec ships could be added?
Well in case of 1st reason it´s up to SSG how they design the ships/where they purchase the models for it so we have no real influence here
2nd reason is up to SSG as well and in theory it gives plenty of combos BUT it gives here the challenge that some combos are simply crap while others are totaly awsome. Atm you see a lot of Pilots flying with the Chrom due the Pilots prefer to have the Prot in combo with OS and Speed. 2nd most used ship from my notice is the Slate due of the QL that allows him to quick travel what makes it the perfect sq leader with good speed an good armor despite it´s "fragile" look.
After this it´s a bit spread but here and there an Obsi shows up or Disru/Hunter so even with all those RDX ships the selection of used ships is rather slim and some ships are only used for Missions.
For the 3rd reason i still stay at my idea that for the RDX ships along with Parsec ships (if new should come) it should give a questline from Vega to Sol that gives us in each system "a part" (Cockpit, Hull, Wings, Thrusters and the CPU) of the new ship and when all 5 parts have been collected the ship will be unlocked/decrypted so that it can be build while the reactor stays optional for the Ifrit Cortex.
In terms of the Event time it could easily be made that each Line of the Mission is locked behind a "timer" so that Pilots can not complete the Event within day 1/2 (Exception is the shop where the parts can be purchased for 25k (same as a set of 5 BPs and so the same costs in total of 125k)). The advantage here is that pilots who may not have the time (or want to keep their sanity) still can complete the ship if they may miss a few days and so may not have enough times to get the Signets to unlock mission A/B + i assume it would feel more rewarding to unlock the ship by an actual mission then just doing the same thing over and over again