It's not only intentional, it's a counterbalance for all the crafting shenanigans. Used to be that if you wanted infinite money, you needed to be able to craft, but that isn't a restriction that makes any sense. If you want to be able to get infinite money, you can do that almost no matter what your build is.
You can still trivially get infinite money by crafting, of course (except on DOMINATING). Crafting + Mercantile essentially == Mugging, since you can walk up with nothing, buy a merchants components, craft them into gear on the spot, and sell them back at such a profit that you walk away with all their money, ammo, drugs, whatever. Buy chem pistol parts from Fixer and sell them back to him; buy tac vest/riot gear/metal armor/SMG/AR/sniper rifle parts from the weapons&armor vendors and sell them back to them; buy organs from the animal parts vendors and schlep them over to the nearest doctor - then buy up their ampoules and syringes, turn the organs into chemicals and those into drugs, and sell them.
Still not ridiculous enough for you? Take the Disassemble feat, carry looted unmodded high-value gear like sniper rifle/AR/SMG/Tacvest/RG/metal armor to the vendors, buy a couple mod components, disassemble the damaged gear on the spot, add the components, and reassemble the item. Presto, now it's repaired and much much more valuable than it would have been otherwise. Even with the 75% value hit, as long as you have a little patience, you can afford absolutely every lavish option in the game if you've got Mercantile, good crafting (at a minimum, Tailoring and Mechanics), and Disassemble.