Based on personal feelings on what you'd prefer the game's technology to represent. I know: I went through a initial phase of referring the SCBs as 'healing potions' myself, but they rationalise pretty easily.
I see shields as the paradigm in ship defence. Like actual armour on the medieval battlefield: Very effective. Sure: You can fight without it, but you're at a disadvantage. It's not 'balanced': Hull is a secondary - semi-porous defence. This is straying onto feelings about what our personal vision of the future is, rather than FDL builds. It's irrelevant because shields am gud, like it or not.
To cut back to topic: Good shields with a hunk of boosters and SCBs plays to the FDL's strengths. Engineer for success, not to reinforce weakness. Sure, you can do it other ways - your ship, your money - but we are being asked for recommendations, and I recommend using the right tool for the job: shield-blag for a FDL.
I'm not sure why the idea of having good shields with boosters and SCBs is a PvP 'Abuse' and locks out casual PvE players? I'm guessing you don't like PvP and you don't like SCBs, but the two aren't strictly linked. It's not like PvPers have the monopoly on doing maths and adapting to the mechanics.
Don’t get me wrong - I like shields a lot: it was my primary reason for selecting the FDL as my main ship for combat. You’re right, I don’t play PvP but I’ve read a number of threads where folks have complained that non-combat ships with a ton of internal space for SCBs can outperform dedicated combat ships. For example: a Python vs a Chieftan. The Chief is supposed to be the combat focused ship and the Python a multi-role but the Python could load up on SCBs, making it VERY hard to kill. In PvE - no biggie, we’re supposed to be able to improve our ships to get an advantage over the NPCs but for PvP I can see why that becomes a problem. To “fix” PvP, I’ve read talk of “phasing PAs” and other weapons that ignore shields in order to give players who don’t “shield tank” an ability to fight against one. Personally, that seems the wrong fix - especially if the casual PvE player winds up having to deal with NPC pirates one shotting your power plant when your shields are up! I’d prefer SCBs be limited to 1 per ship or something like that.