This article was pretty lame, and it did not have any supporting facts, it simply aired a few gripes, and most of the gripes are from guys on the sidelines, like a former SEAL who couldn't tell blank from live ammo during a training mission (I'm sorry, but I couldn't finish Marsinko's book after that).
The issue isn't misuse (although it will happen on occassion), it is operations tempo, so the author missed the main point. Once deployed you're deployed and guys want to do worthwhile work while they're deployed. In some locations guys had to search for missions, while in others they were begging for a break. I don't think it was different in past wars.

Back to the issue, unlike Afghanistan in 2001/2002 when SOF and conventional forces were still feeling each out, they now work together much better, with some hiccups in places based on personalties, so comments like SOF should never support conventional forces are way off the mark.

What is really nice about our relationship with conventional forces is when the crap hits the fan, and there is a fellow American fighting man outside the wire, everyone will come running to help. SOF helps conventional forces and vice versa, so if they ask for help, we generally try to support them in a SOF appropriate manner. pmcr hit the nail on the head with his comments.