While I don't think that you can get reliable stealth abilities from gear, I definitely understand what you brought up and find it valid.
Yet I don't know how can anyone get 200 points from gear. Could wear a Balaclava and Black Cloth Tabis with some Overcoat, a Cloaking Device (that depletes within seconds) and you're lucky to get to a 100 maybe. Which is not enough for anything and basically only allows you to bypass the Initiation check and start combat... from afar. Which is not advised for a non-stealth character, as now he's stuck wearing that armor for the entirety of the fight. At that point, he should actually focus on Stealth for good and embrace all it's combat benefits, use Ambush, etc.
I also find it ridiculous and lame to carry all that gear and change completely every time he wants to sneak by.
I think one either maxes out Stealth or leave it on zero. No point in putting just 100 points into it and rely on gear to boost it further, as you loose all the cool combat benefits from related feats like Snipe or some melee knife abilities. Also in situations and quests where it's useful, you also need every point you can get. Navigating the Grey Army Base and looting everything (including all lockers)? Attaching explosives in the Tin Can base for the Free Drones without getting exposed? Trying to walk past a tunnel full of Burrowers and their spawns? Not something one can do with just gear and sure as hell impossible without Interloper. Specializing in a few things to solve most problems and not bother with others is the way to go in this game opposed to dipping in a lot of abilities. In this regard it's similar to an immersive sim. There are more than one solution for something, so you can get higher with a 10-step ladder instead of 3 with just 5 steps each.