Light wheels wear out sooner and get wrecked easier. You need a 700c rim, let’s say. You’re riding 38mm to 45mm tires. You ride in the rain, too. You weight 198lbs and ride bad loads, with small-to-midsized loads. You have no business riding a rim skinnier than 22mm, or one that weighs less than 480g, or has fewer than 36 spokes (rear wheel, let’s say). You want thick braking surfaces that give you extra wear in gritty conditions. You want a thick spoke bed that resists cracking under the tension of the spokes. You want a braking surface that’s at least 10.5mm tall, so adjusting the pads doesn’t require surgical precision, and the pads, if they’re not honed in perfectly, still land on the braking surface, not on the tire above it or the air below it.
All up all those desirables, and you’re up to 480g, easily.
Personally, I ride those tires. I weigh ten pounds less. I ride all year, all weather, and my rims suffer grittiness a lot. I want an extra hundred or even two hundred grams. So what? I don’t want wheel problems. I do want longevity. Give me heavier rims, and let me put a heavier tire on them. Let my wheel weights fall where practicality casts them. That’s the way to do it.
Heavier wheels are more difficult to accelerate, but acceleration is a micro fraction of the time you spend riding. Heavier wheels maintain they’re momentum better, and that’s a huge key thing. At some point a wheel can be inefficiently heavy and clearly not desirable, but in the world of aluminum rims and air-filled (not solid) tires, it is hard to put together a wheel that won’t benefit in some real, practical way, by a few extra ounces. It doesn’t hardly matter where the extra ounces come from. Heavier rim sidewalls = more durable braking surfaces and more dent-resistance. Thicker tire tread = more puncture resistanc and longer wear. Thicker spoke bed = no cracks in this highly stressed rim area. Thicker tire sidewalls = more sun resistance and less likely to get cut.
Stout, reliable wheels let you ride more place, under more conditions and for a longer time—years longer, in some cases.
That doesn’t mean you should never go light. If you have several bikes and want to give one a superlight personality---along with the limitations that come with it---then have fun with the lighter wheels, but don’t expect them to last as long.