[tobyhill]

I've bought a 3 lawnmowers in the past 3 years and now I know why.

[Eric in the Ozarks]

Most likely it is the solvent quality of the ethanol that causes damage. If the string trimmer is old and little used, the alcohol, oil and gasoline will separate and a straight dose of gasoline (without the oil's lube quality) will destroy the little engine.
I have used ethanol blended gas in my '95 Toro 4 stroke, both my two stroke chain saws and a two stroke trimmer without any problems.

[WoofDog123]

alternately, where were they made?

I have found many small home appliances/mechanicals have been moved to manufacturing in China over the last several years, and even brands with trusted quality are selling junk now that breaks within a year, or never works right from the start.

I dread buying a new washer/dryer/frig.