Gonna has to go piece by piece through this:

obviously everyman has had a dick in his hand for obvious reasons.

This line is trans-exclusive, which would probably be given a pass by all but the most ardent trans-inclusive commenters, but still not great.

And all females

Dude. There are some times when an argument is made that saying "females" is not inherently objectifying, especially in a scientific, military, or other setting where people are categorized that way, with the significant difference being consistency (e.g. man/woman, male/female, etc). Using one then the other strips all that away and makes it seem like referring to women as "females" is just your normal tendency, which strongly suggests the objectifying behavior.

And all females old enough for sexual interactions have had one in their hand.

This is just obviously wrong, as plenty of lesbians, asexual people, or those with lack of access to sexual connections with others have not had a dick in their hands, and that is not an insignificant percentage of women, I'd imagine.

The next time I shake the hand of a woman I am going to wonder how many dicks she has had in that hand.

As if to underline the "females" comment, it's pretty telling that you feel it worth mentioning that you're going to wonder how many dicks were in the hands of women, but not men (especially funny since any man you meet has most likely had a dick in his hand more recently than a woman).

Sometimes it is difficult to notice your own biases, so I hope this makes you think about what leads you toward thinking like this, and just general self-reflection.