Because there is a reason why certain races don't have certain things and many of us feel that handing out magic items to take away every disadvantage is not something we want in our game. I feel this way as player as well. I hate the whole magic item shop.
Why exactly do you hate it?
I find it implausible that they would not exist. Not necessarily as a shop per se, more like back alley deals. Magic items are worth a lot in a D&D campaign setting. Anything that is worth a lot should have commerce surrounding it. Not doing so seems bizarre.
The reason it would often be back alley deals is due to the value of the items. A shopkeeper, shy of being in a large protected city, might not be able protect himself from thieves and other nefarious NPCs.
I equate this to real world weapons. In the U.S., most adult Americans can buy handguns, rifles, and shotguns (i.e. +1 daggers, swords, bows). They cannot acquire fighter jets or tanks or even AK47s or dynamite. At some point, society says "enough is enough" for weapons.
But, there is a black market in the real world for the more powerful weapons.
The same type of economics should apply to a D&D world. +1 weapons, armors, and common items like bags of holding should be available. Expensive maybe, but available.
The more rare and valuable items should only be purchasable from special unique merchants who deal solely in high end goods, or via a black market.
There is also a lot of roleplaying potential for having an NPC that the players go to for high end items. Such a PC has magic item crafting and trading connections, but might require PCs to go on quests to gain components or whatever. This also allows for a reoccurring NPC that the PCs might start liking and wanting to be protective of (i.e. a reoccurring ally).
Higher magic items should be part of a quest or finding and paying a wizard to make it for you.
Or even crafted by a PC spell caster at higher levels.
I certainly think it is an issue when players start complaining about a disadvantage at first level.
Agreed.