I am with Boatycall that alternators can easy take it and even more.
I had 30 amp alternator on my boat yet I did not hesitate to use 1500W oven (via inverter) with single battery.
Sure high load will wear out the brushes faster and those seem to be available in voltage regulators only, but even the top VR doesn't cost more than $50.
I think the problem is that replacing alternator brushes is very often neglected maintenance and Murhphy law says they will give up 300 miles from electrical shop
Than if you have generator, you do have backup and when alternator died on my Superduty, with dual batteries I was able to make over 100 miles to parts supplier.
No blower, no AC and no lights and the battery can run the engine for long time.