Mirroring and minus scale

Hello. I noticed something weird in Acad 2010 and would like to confirm if this is normal or maybe 2010 specific problem. Whenever I use "mirror" on any block, Acad always modify X scale by multiplication it by (-1). It doesn't matter which axis is chosen to mirror (X, Y, or angle). Of course setting it again manually to + doesn't revert the mirroring effect or rather it creates new placement basing on base point.

This minus scale on X is unwanted because it creates issues with visibilities on dynamic blocks when explode attributes to text is used.

EDIT: the problems with dynamic blocks and visibility attributes are:

1) if block scale has (-) in X (didn't check for Y or Z because mirror doesn't change this) then after "exploding attributes to text" the objects which were on hidden state doesn't dissapear but stays hidden (there is no way to display them, even select them is hard, only select all works here) and if such DXF is imported into Inkscape then these hidden objects are visible.

If scale X has no minus then after "exploding attributes to text" the hidden objects just dissapear completely.

2) Inkscape 0.92.3 can't import elipse objects properly if the block contained such elipse had - in X scale.

AutoCAD has always done that when you mirror blocks: looks like you simply want to move the block instead of mirroring.

Or stop using TEXT inside blocks and use ATTRIBUTE type text objects instead; these will mirror an correct themselves.

I don't use text objects in these blocks. It is funny but "exploding attributes to text" does more than exploding attributes to text. It explodes anything what was in block overwritting objects layer settings with the one made for block (if elements in block had layer set to 0). Normal explode doesn't do that. It is much convenient to prepare exploded objects for Inkspace. But this -1 X scale generates issues with visibility. It seems that this is an Autocad bug then (not the -1 X scale but the fact that in one case exploded and hidden objects just dissapears from drawing, and in other case (-1 X) the object stays in drawing but is invisible).

Go beyond the core commands then: how about posting in the LISP forum for help writing a LISP that mirrors them fixes your block for the -1 setting, or are you stuck using LT by chance?