That is highly unlikely, such a mundane job as a sysadmin compared to having your own online business.

If he liked it that much, then probably he wouldn't have started a whole side project that must have consumed evenings and weekends for years.

If he would have found professional fulfillment in his job, he would not likely have started a side project in the first place.

As he mentions in his own reply, he stays because he feels that his job defines him as a person, and he would lose his social identity if he left.

This is a surprisingly lucid reply, he can do whatever he wants and I wish him the best, but it's clear to me that he has other much better options available.