I agree. To me, this is just an amusing fashion choice. If you're gonna need the gear, so you may as well have fun with it.

Honestly, when it comes to any accessory or tool, it's going to have an aesthetic. Who cares what that is (as long as it's not offensive). There's also a tendency to consider terms like 'fashion' to be emasculating, but that's what this is: fashion. Plus, kiddo isn't going to care about logos and any gender representation; the only shit they're giving is in their pants.

Other fashion choices for diaper bags that could be explored:

• Metal (leather/pleather, spikes, denim, band patches)
• Goth (like above, but with less denim and more ankhs and crosses)
• Gamer (cosplay appropriate bags, pokemon that's also a bag, D&D mimic on a shoulder strap)
• Sports (tons of practical and team-branded merch options here)
• Office (suit material, inoffensive beige, briefcase handles and leather)
• Handyman/tradesman (toolbag or toolbelt aesthetic, tool manufacturer branding)
• EMT/firefighter (first-aid compartment, red/white aesthetic, cheeky "diaper emergency kit" on outside)
• Outdoorsman (gore-tex, tent material, typical REI brands, lots of straps for different carry options)

Edit: not a dad. Some of these may already exist. Point being: it's all a matter of taste.