Yeah, god we're such shitlords, aren't we? Time to go give myself some lashings at my home built shrine to Ellen Pao.
Seriously though, this is entering the realm of stupidity. You made an assumption based on your own experiences (that the vast majority of computer programmers and enthusiasts are male) and one that is backed up by data - the vast majority of computer programmers and enthusiasts are male.
Coupled with that assumption is the many other various "I'm teaching my kid to program" blogs and similar that pop up here from time to time that to date, as far as I recall, have all been written by men. A story about a programmer is highly likely to be male. A story about a programmer regarding their son wanting to learn programming and them teaching them is likely to be a male teaching a male.
When women are showing the same level of interest in computers, in programming, in computer science, etc. as their male counterparts and are blogging, developing, taking part in the community at the same level, then it may be questionable to automatically assume it must be a man teaching his kid to program.
You are as sexist in your assumptions here as you are in your transphobia in automatically assuming the son is "cisgendered".
C'mon now, let's take a large step back from this nonsense.