That's what we were promised, instead we got the CCU system because it suited CIG better. Now, the grey market and the people that "gamed the system" is getting the blame. It's just not fair.
Of course, CIG would rather you buy a new ship than exchange your old one. We can't blame them for that.
Take this example: I have a Cutlass and I'd like to CCU it to a Corsair. I'm okay with paying the $115 difference. If I change my mind, I'd only be able to get back the Cutlass 4 times a year, considering it's the only thing I want to buy back. I don't know enough about the Corsair (and have no idea when it will be flight ready), so I can't be 100% committed to it. What if it's shit when it actually comes out? Am I willing to pay the full $215 to get it and then melt it if I don't like it? No, that's a $100 price difference. Also, I'll lose the LTI (the utterly useless yet game-changing LTI) on the Cutlass if I CCU it and then melt it, so I'll need another buyback token to get another LTI base ship. So I decide I won't get the Corsair.
I've been in this situation for the last couple of years.
90% of my contribution to Star Citizen was until about 2 years ago. Since then, I feel that my investment isn't flexible enough to be worth it to me, so I just stopped buying ships.
I'm not saying my logic is flawless, I'm just explaining why I'm not buying more ships even though I have money to spare.
EDIT: I've bought an Endeavor a long time ago and it's still a long way from seeing the light of day. For my frozen $350, can I test the new ships that become flight ready? I can't. Not without juggling buybacks and CCUs which clog CIG's databases.