You don't need to make your source public.
Just check it in as private repository and your contribution graph is going to be filled.
Some recruiter can now see that you work a lot - probably also on weekends and so on.
A good looking github contribution graph looks kind of professional, also if you have starred some repositorys (which probably means you are active and love what you are doing)
A developer who loves his job/hobby also codes in his free time (because it is also a hobby)
Of course, if being a develoepr is only a "job" - this sucks.
For example, I am coding 8h+ a day during my fulltime job. When I am back at home/weekends, I also spend a lot of my time to code private projects instead of playing games
Someone can certainly enjoy their job--and software development is certainly nothing special--without also wanting to spend their nights and weekends doing the same thing. For that matter, I'd probably take such a narrow set of interests as something of a disqualification.
I realized that passion to your work has a huge impact to your application.
If you are software developer (what I excect) and have a job - yeah it is a valid opinion. If you don't want to code in your free time it is up to you.
It doesn't mean that you have a narrow set of interests. It just mean I use a part of my free time to code.
Others are watching tv, playing games or doing other time wasting stuff.
And others are spending time with friends, families, taking care of their sick relatives, their kids, going hiking, reading, volunteering, etc.
There's no need to say X is "wasting time" in such an objective tone. For many, spending hours on the weekend doing programming is a waste of time (and it can be, most of the time). For you, it's fun. For others, they just don't have time to do it. No need to judge or expect others to live the same life as you.
I only just noticed that you can make private contributions show up on your contribution graph- still there are lots of reasons stuff might not show up on there.
A good looking github contribution graph looks kind of professional, also if you have starred some repositorys (which probably means you are active and love what you are doing)