The reason why I am against state patriotism is because I am gainst patriotism in general. It is a very strong force within a society and one that does not always have the desired effects. Therefor I consider patriotism quite dangerous. Patriotism also has good effects no doubt there. But I am against every force that could become uncontrolably. Patriotism comes very close to Nationalism (and I sure as hell don't like that) So that's why I am against patriotism in general.
Now about state patriotism or whatever subform. To me patriotism is only possible when you have something to be patriotic about and to define what you are patriotic about you need boundries (else you will be patriotic about everything which has no point) Those boundries (IMO) are set by cultural differences. Like e.g. the UK has a different culture than the US. altho the difference between most countries (certainly in the same region) is quite small. So the margin for patriotism (IMO) is already small on a national scale. to go and divide it even further into regions and states is just too silly in my opinion.
It would also not help the unity in a country which IMO is far more important then being patriotic about your own region.