A lot of people don't ever get a trainer to show them the right way to do things and get hurt. The people who do learn the right way will find benefit in isometric training. Telling everyone to ignore it benefits neither group.
It's certainly important to exercise muscles with a full range of motion, but even people who don't do isometrics hardly ever train to their full range. Watching people at gyms do push-ups, pull-ups, squats, lunges, hell even lat raises with only a specific range of motion is sad.
Isometrics are a specialist tool, they don't make much sense for the general case. Turning to them first is like saying "gee, our web server is a bit slow. Let's tinker with making cron run faster".
It's certainly important to exercise muscles with a full range of motion, but even people who don't do isometrics hardly ever train to their full range. Watching people at gyms do push-ups, pull-ups, squats, lunges, hell even lat raises with only a specific range of motion is sad.