Why matrices cannot index vectors in Julia

Question

TL;DR: I am trying to understand why Matrixes cannot index Vector objects in Julia. Apparently, a vector can index a matrix (see below), but the reverse is not legal. I want to understand the behavior because (1) I don't understand why it does happen and (2) I assume this is preventing the programmer from screwing things up, but I cannot see what this behavior is protecting the programmer against. Thank you very much.

---

Consider the following arrays.

julia> x_vector = [3 ; 2  ; 1]
3-element Vector{Int64}:
 3
 2
 1

julia> x_matrix = [3 ; 2  ; 1;;]
3×1 Matrix{Int64}:
 3
 2
 1

julia> y_vector = [1 ,0 ,0]
3-element Vector{Int64}:
 1
 0
 0

julia> y_matrix = [1; 0; 0;;]
3×1 Matrix{Int64}:
 1
 0
 0

Now, I will use the y arrays to index the x arrays selecting the value that contains a 1 in the y arrays.

Below I listed the trivial cases (i.e., matrix indexing matrix and a vector indexing a vector)

julia> x_matrix[isone.(y_matrix)]
1-element Vector{Int64}:
 3

julia> x_matrix[isone.(y_vector)]
1-element Vector{Int64}:
 3

Apparently, I CAN use a vector to index a matrix.

julia> x_matrix[isone.(y_vector)]
1-element Vector{Int64}:
 3

However, I CANNOT use a matrix to index a vector, even though they have the same dimensions (do they?).

x_vector[isone.(y_matrix)]

ERROR: BoundsError: attempt to access 3-element Vector{Int64} at index [3×1 BitMatrix]
Stacktrace:
 [1] throw_boundserror(A::Vector{Int64}, I::Tuple{Base.LogicalIndex{Int64, BitMatrix}})
   @ Base .\abstractarray.jl:691
 [2] checkbounds
   @ .\abstractarray.jl:656 [inlined]
 [3] _getindex
   @ .\multidimensional.jl:838 [inlined]
 [4] getindex(A::Vector{Int64}, I::BitMatrix)
   @ Base .\abstractarray.jl:1218
 [5] top-level scope
   @ C:\Users\index_matrix_vector.jl:34
 [6] eval
   @ .\boot.jl:373 [inlined]