The industry's changed since Deadly Shadows was released, and my standards have risen. We've already gotten a bunch of reasonably faithful successors that weren't dumbed down, and an impending wave of new, promising late-90s-PC-style games (mostly through Kickstarter). Stealth gameplay, specifically, has been on a high recently. Like Mark of the Ninja is probably the richest stealth game of all time, for example. Even Eidos' own DX:HR made some advancements. The point is, we don't have to be begging for scraps.
That's why if I'm going to be severely disappointed if Teef is only Thief 3 quality. Developers who work in the space once occupied by smart PC games shouldn't be getting free passes any more.