The worst thing is how it degrades public trust. There's nothing wrong with SWAT teams, if they're used as needed. For hostage situations, for example (which is how they were sold to the public). Even then, however, they shouldn't be used in lieu of trying to talk someone down. Now they're used for everything, and every police force has their own team, funded by federal dollars and what they can seize.
SWAT teams are like guns, or fire - they have to be considered special tools for special things. When you need them, you REALLY need them. And when you don't, you REALLY don't. A society advances to the degree it can properly use it's growing power. When the power outgrows the proper use of it, it ends up devouring the very society it purports to be serving.
Absolutely spot on.
SWAT are specialists, and so they should be. Got a friend who is a SWAT sniper. 95% of the time she works as a normal cop with her regular partner who is also her spotter.
She has said that they are being called out more and more often for things that would ordinarily be done by the regular cops.
She is mega peeved at it - compares it to using Marines to break up a playground fight, plus it throws their shifts all to hell.
Mostly it is political. Mayor wants to look tough on crime? Use the SWAT team. Budget appropriations due? Use the SWAT team to keep the funding.