According to an official army publication, "in the fight against ISIS, former President Obama dealt President Trump a winning military hand". To me, a "winning hand" is hardly doing nothing.

I recommend the following:
https://ssi.armywarcollege.edu/index.cfm/articles/Strategic-Questions-Loom-Large/2017/04/11
http://usacac.army.mil/cac2/Repository/Materials/COIN-FM3-24.pdf
http://www.dtic.mil/doctrine/new_pubs/jp1.pdf

Read these, then you'll understand the negativity...