I think you know best if your kid is going to be having sex in your home at 13 or if he hasn't realized girls are the same species yet and thinks video games are the reason for his existence. It's not fair to judge him based on your husband's behavior!
My mom stayed at home but oh how I cherished the time I could get home alone when I could get out of a family outing or errands! I probably started getting stretches of a few hours at 10 or 11. Eventually my mom would start leaving me chores like do the dishes or vacuum; they wouldn't take the whole time but added a little touch of responsibility to the whole thing. Around the same age, 7th and 8th grade, I would go home once a week with a latchkey friend who was an only child. The initial plan was to trade off week-to-week, but then they got a puppy so my friend had to go let it out. We'd heat up a snack, watch Boy Meets World, chat, play with the puppy, etc. Admittedly, we were pretty responsible girls and didn't have much inclination for getting into trouble. It was fun times though, and interesting for me to escape the relative chaos of my house (sisters were 4 and 7 at the time...)
Between 15 and 17 I started staying with my sisters all day (literally morning to night) and eventually overnight, which had as much to do with their increasing maturity as mine. I didn't get paid and they hated getting bossed around by me so this wasn't really high-quality babysitting; we'd eat in the living room and go to bed at least an hour late and have unlimited screentime. But everyone lived and I think I even cleaned up a little. At 16 I had my first serious bf and would often head over to his house after school; sometimes with other friends but often without. In retrospect we could have been doing anything, but we didn't. And if we had, it would have been better (safer, more legal) than anyplace we might have found, had our minds been set on messing around. I've no idea if he took advantage of that with any other girlfriends, or how his parents (would have) felt about it; not something that comes up often in conversation, as you can imagine.
So I think the answer to your question really depends on your kid. If he's reasonably responsible about his homework, chores, and other obligations, if you've talked about sex, alcohol, drugs, and other teenage vices and he has adopted your rules as part of his personal convictions because he knows there are solid reasons behind them; if has a good head on his shoulders overall and isn't apt to set off fireworks indoors or something...then being afraid to leave him home for 2 hours a day seems rather overprotective. If he's prone to lying or sneaking around, doesn't have much respect for you or the rules you set, is very interested in his peers' opinions and in being "cool" now rather than successful later...then maybe he really does need a couple more years of your guidance. If he's somewhere in-between, as he probably is, why not try scheduling some errands, appointments, or a sport/hobby in the after-school hours and see how he responds to occasional alone-time, before committing to a job?
Or, from a totally different perspective, maybe this is more about you than him? My mom worked occasional part-time things starting when my youngest sister was in middle school; in her last year or two of high school, she considered going full-time (responsibility-wise it wasn't a problem), but ultimately she really wanted to get the most interaction out of the last few years with her youngest child at home. It wasn't about controlling behavior, but about being around for and amassing all those little moments.
