Slop.

To set out my case further, I rest my argument on four main contentions: 

1. The colonial history of the words ‘pan-Islamism’ and ‘Islamism’ is inextricably tied to the notion of a threat that requires a security response.

2. The contemporary popular use of the word ‘Islamism’ is nearly always tied to militancy, extremism and violence, and so cannot be rescued from within academia. The evocation of the word presents images of violence. Unlike words such as ‘Muslim’, which may now be regarded in the West as evoking similar fears, ‘Islamism’ operates as a hydra, where it is simultaneously violent and meaningless in its operation. Violent, in the impact it can have, meaningless in the amorphous nature of its use. 

3. That within the framing of the global War on Terror, the accusation of ‘Islamism’ in itself draws heightened suspicion and surveillance, leading to many forms of violence enacted by the state. Similar to the framing of the ‘good’ and ‘bad’ Muslim, ‘Islamism’ carries a significant degree of academic cover that operates outside of its ubiquitous significance – academic use cannot rescue the way the word has been politically instrumentalised. 

4. It presupposes that only certain forms of faith-based political expression are ‘Islamist’. I make this point to suggest that quietist expressions of faith within the political realm, are no less political in their maintenance of political authority – indeed these positions are often used to uphold that authority. 

From: The case against "Islamism"

So yes, it is a confused way of saying "Muslim" and is deliberately used by colonizers to 'other' the politics outside of the Imperial Core. It's the same as when people say "I'm only against illegal immigrants, not legal immigrants." Except it's accepted among the "left" because of ISIS being reactionary and 9/11.