You don't have to use the new system if you have so many gripes about it. You can always go back to removing mods from your gear each time you wanted to change your outfit and then we can read your complaints that 250k to remove your mods is a bigger waste of credits then just the 35k for the slot. In fact, if you do the math, changing your mods out 16 times at max lvl (max slots available) it will already set you back 4 million credits which is roughly what you would be at by just purchasing the slots with credits.
Additionally the slots cost fluctuates depending on the lvl of toon so alts and new players will not be crippled by having to spend 35k to change the look right away.
Level: / Cost/Slot / Full outfit
1-10 /50 credits /350 credits
13 /300 credits /2100 credits
16 / 600 credits /4200 credits
17 /700 credits /4900 credits
19 /900 credits /6300 credits
23 /1300 credits /9100 credits
55 /4500 credits /31500 credits
60 /5000 credits /35000 credits
Nobody is forcing you to use the new system. It is an option there if you chose to use it, to save credits in the long run.