2500-3000 hours is about right for a GX motor running at full load. No oil filter and lots of heat. Thats roughly equivalent to 100k on a truck engine with a life of mixed city/highway mileage (30-35mph lifetime average) and they have comparatively pampered lives with good oil filtration and steady engine temps and usually get a chance to warm up some and rarely ever run at full output.
These small OPE engines start up, run WOT at or near full load most of their lives with no oil filtration, little to no warmup and little to no cool down before shutdown. Not to mention rarely getting maintained per the manufactures directions.