No it isn't. Shape and weight are a matter of comfort and usability. They have nothing, absolutely nothing, to do with whether a pen is feminine or masculine.
The argument about shape and weight is justified.
Only things with reproductive parts can be feminine or masculine. (i.e., living beings.) Everything else is just a false association for the sake of making one person feel better about their personal choices, at the expense of making someone else feel bad. It is all nonsense. Don't buy into it.
Edited by fyrstormer, 13 November 2012 - 18:31.