No, that's unreadable code and therefore not idiomatic.  The typical way to generate large numbers is to use multiplication.

`"Hello, World!"` translates to ASCII values

    < 72, 101, 108, 108, 111, 44, 32, 87, 111, 114, 108, 100, 33 >

… which can be thought of as

    10 * < 7, 10, 11, 11, 11,  4,  3,  9, 11, 11, 11, 10, 3 >
       + < 2,  1, -2, -2,  1,  4,  2, -3,  1,  4, -2,  0, 3 >

The code should therefore be written that way.  The consecutive elevens can lead to a compression optimization.

    +++++ +++++ [- >
     +++++ ++ >
     +++++ +++++ >
     +++++ +++++ + >
     ++++ >
     +++ >
     +++++ ++++ >
     +++++ +++++ + >
     +++++ +++++ >
     +++ <<<<< <<<<
    ]                        Print:
    > ++ .                   "H"
    > + .                    "e"
    > -- .. +++ .            "llo"
    > ++++ .                 comma
    > ++ .                   space
    > --- .                  "W"
    > + . +++ . ----- - .    "orl"
    > .                      "d"
    > +++ .                  "!"

For readability, you should also group the increment and decrement operators in fives.  I also find your comments unnecessarily verbose.

This solution uses one more memory cell than the original code.  It's well worth it for the readability, in my opinion.