Pablum. This is the myth that just refuses to die! I have been running E10 for more than ten years...ZERO, ZILCH, NO PROBLEMS to report.
No, not pablum.
ETOH fuel dried out all the gaskets on my motorcycle and one of our small 2-cycle outboard motors.
The stuff is total shit for small engines.
Horse shit. I have run it in no less than a dozen small engines (many of them 20+ years old). The sum total of the problems resulting was having to clean out the carb on a 20-year-old leaf blower when the alcohol loosened years of crud in the fuel system. Cleaned it out, I'm still using that leaf blower. I have run my old (late 70's!) generator for easily 1000 hours on E10...it ran 19
days straight at one point without a hiccup. My wife's old motorcycle (1979 Suzuki) had no problems with E10. None of the half dozen vehicles I help prep for winter storage have had a problem.
In your case, I suspect operator error.