Lua's 1-based indexing is largely inspired by Fortran. Lua's first users were Brazilian engineers in the early 90s, who were mostly experienced in Fortran.

Arguably, one-based indexing is more closed aligned to mathematics tradition. That point about being easier to index the last element helps to iterate backwards over an array. With zero-based indexing, a backwards loop becomes for(i=N-1; i>=0; i--). Yuck.

I meant that aesthetically, I find 0-based indexing more appealing.

Yea, I love how 0 indexing is such a big deal. Like tabs vs spaces, it doesn’t matter even a tiny bit, it’s like a religion. It’s not that hard to index off of 1, and like I said, you can write like 5 lines of code to make 0 indexing the default!

I think it's just common sense of pointing to the first location and saying "one" ("first element"), "two" ("second element") and so on.

Requiring a keyword to declare a variable is a good thing. Otherwise, it'd be easily to accidentally declare new variables when you meant to assign to an existing one. Since global is the default, starting a program with something like this effectively keeps that from happening:

  local gindex = {}
  setmetatable(_G, {__index = function(t,k)
    local v = gindex[k]
    if v == nil then
      error("Bad read of global variable " .. tostring(k), 2)
    else
      return v
    end
  end, __newindex = function(t,k,v)
    error("Bad write of global variable " .. tostring(k), 2)
  end})
  for k,v in pairs(_G) do
    gindex[k] = v
    rawset(_G, k, nil)
  end