That it didn't fit into the expectations of the late teen and twenty-something punters that buy most new MX bikes.
That it was 'weird', with the kick-starter on the left.
That there weren't ten dealers within 50kms of your house.
That the way it made power, and handled, was significantly different to the jap bikes of the day and didn't/doesn't suit our tracks as well as the jap bikes.
That they still needed 'the touch' to get them working perfectly.
They still had relatively clunky gearboxes, forks with a big mid-stroke spike, and brakes that lacked bite - which were typical of the Euro bikes of the era and are tangible failings compared to the Big$'s offerings of the day.
The 88 KTM125MX I owned was not a patch on the 88 KX125, esp not on a typical Australian MX track. Hell, an 86 CR125 is significantly better than the KTM.
Give me a Euro style, rough natural terrain track covered in heavy loam, and I'd seriously consider the KTM as a race bike of choice.