1.Is the class "designed around it"? Certainly not. None of 5e is. Everyone and their mother has "spells"...not jut magical abilities, spells. The only three "martial" classes each have a magical option and then the monk gets their magic-like "ki" powers...which, in my opinion should have been used/duplicated in reflavored form for the Paladin powers instead of actual spell-use. BUT they, apparently, wanted to set up the paladin and ranger as "half-caster" options...so, spells fer ev'rybody!
2. But it is playable...and it is no more "suboptimal" in combat than playing a fighter. Sure, might lag behind in this or that...no action surge. Big woo. So the fighter fights better...as it is supposed to. The ranger will be comparable to the fighter against certain foes/combat situations and better than the fighter in outdoor/exploration situations...as the ranger is supposed to.
There are choices to be made as a player. One of those, if I want a "by the book martial ranger" is to refrain from using spells...or only take/use "spells" that I can refluff into (and work out with the DM/table that they are, so we're all on the same imaginative page) non-magical ability/training/specialty. .....
3. Would I, personally, have preferred a spell-less base ranger with spell-variant subclass. Yes. We didn't get that...and it would appear are not going to get that in a style I find acceptable...because it doesn't mesh with WotC's designer's preferences/specifications...SO, I wrote up my own. But I don't/didn't HAVE to to get/play a martial ranger (if that's what I wanted). Everything I would need to do that is right there in the pages.