Especially when there’s no overtime pay, this is a virus that can rot a team. A few hours of passion-led overtime can quickly morph into crunch when the employee no longer wants to stay late (reasonable!) but the scoped work was (implicitly) counting on that extra time.
If you’re an employee - don’t do this unless you’re getting paid. Just because you’re passionate doesn’t mean you shouldn’t be getting paid in equal measure. But also be aware of burning yourself out! Burn out is real, and no amount of money is worth you going through that.
If you run a company, be aware of any “secret” work that you are implicitly relying on (or doing) for the delivery of something! IMO block it all together if possible, or find ways to incorporate it into the main stream of work in productive ways.
I also say all this as someone who’s been on both sides of this in different permutations. 80 hour weeks with no overtime. 60 hour weeks with overtime. Both suck, and neither was worth it for what was produced in the end when I consider what else that did to my mental state.
Worth noting too: the “passion to keep working after work” will ALWAYS go away. People have kids, burn out, family stuff, health issues, new hobbies, whatever. Relying on someone’s (or your own) “passion” is a recipe for burn out and mismanagement.