"Even if you accepted the notion that Islamophobia is a term so ill-defined or even tainted with dangerous connotation..."

Stop right there. That's all that is required to oppose the motion on objective, practical grounds. It is ill defined and tainted with dangerous connotation. No obfuscatory appeal to "claptrap" whether "high-pitched"(?) or otherwise.

One need only point to the Southern Poverty Law Center's own labelling of liberal, muslim reformers with the slur "Islamophobe" to see that the term finds use primarily as a brickbat with which to beat blasphemers, and is only marginally useful as a term to call out bigotry against Muslims, when we already have clear words for that, like discrimination, prejudice, etc. 

The primary target and victim of Islamist terrorism are Muslims, but it plainly makes no sense to refer to such violence done in the name of Islam as "Islamophobic", but it makes all the sense in the world to call such atrocities "Anti-Muslim", or, simply, murder.