Hussar
Legend
Why should D&D well support a play style that will fully ignores half the classes and all of the magic items that are part of the core D&D experience ?
You are trying to impose huge limitations on a game that wasn't designed to accommodate them, and then complaining that it doesn't leave you many options that fit your narrow requirements.
Thing is, this was the more or less default play style for about the first twenty years of the game. In OD&D, and 1e, your "full casters" had an extremely truncated spell list, and, even with a fairly generous DM giving the Magic User a lot more spells to learn, the MU just couldn't cast that many spells in a day. Just didn't have that many spells to cast. Even at higher levels, say, 8th+ (higher in AD&D anyway), at best your MU was casting maybe one or two spells per encounter, and even then, likely only one. Clerics didn't get any direct damage spells (that I recall anyway) until FOURTH level spells. The idea of cleric as blaster simply didn't exist.
Never minding that the standard party was three fighter types, a cleric, wizard and a thief. You had four of the six characters with no spells at all (for almost the entire campaign) and the cleric mostly dealing with healing and the wizard shooting off spells at a much, much lower rate. Add to that the fact that most magic items were nowhere near as flashy as 5e items - a flame tongue, which was a major magic item, was a +1 sword most of the time. At best, it was a +4 sword. Not the 2d6 bonus fire damage every single hit of 5e. Magic armour and shields were pretty much plus items only - no other effects. By and large, there was no visual difference between a fighter with magic weapons and armour and one without.
5e is a MUCH higher magic game. Most classes can cast spells. Most encounters feature spells being cast every single round. There might be a lower expectation of the number of magic items in a given campaign, but, the items tend to be a lot flashier than in AD&D.
If the goal of 5e was to support D&D play styles, then supporting a low magic (I'd agree that a no-magic campaign is not something D&D should support) game which was a very common play style in 1e and 2e, should not be too much of a stretch.
I do agree with [MENTION=2067]I'm A Banana[/MENTION] though. The options that we do have should be able to cover things well enough. I'd like to see a few more options on the low magic end of things since the high magic end of the stick gets a ton of support, but, I don't think it's too hard to do low magic 5e. About the biggest issue would be healing and 5e doesn't really need in-combat healing that often. I mean, I've seen it done now that you can run a game without a standard healer at all - our current group is almost 9th level and the only one with any direct healing is the Paladin and that's what, 40 points per day? In a 6 PC party? Not a lot of healing there, but, it's not necessarily a bid deal.
What casters bring to 5e is breadth of options, not so much straight up depth of power.