The edges of the bezel reminded me of my Seiko Monster (you've seen that one of mine, I believe).
Totally agree with you about the ruggedness of these inexpensive tool watches, they are sturdy and no non-sense.
However, perhaps a big reason that they are perceived to be more "tool-like" is that their low price-tags allow us to wear them freely without worrying about scratches and chips...
IMHO, I think a true "tool watch" has to be inexpensive (or extremely scratch resistant, as in the case of Sinn) and to allow its owner to wear it in a totally free manner, both physically and psychologically. I never treat my 18K Daytona as a tool watch.
The one that you have there, JX, is truly a "tool watch".
Enjoy!
Jon