I agree that is very weird at first. But after building a toy project including about 5,000 lines of Lua, I can say I got used to it fairly quickly. Most of the time, I was accessing arrays via iterators anyway, so I had to deal with indices very rarely.

Aesthetically, it is repulsive, but when actually writing code in Lua, it was not much of a problem. I felt much stronger about "do"/"then" and "end" versus curly braces for delimiting blocks.