"There isn't, and they don't."  You can't say this any more than others can claim that there is, and they do.  Using the same documents (I assume) that you have read, all you can say is that, given the large inter-annual variability of hurricane frequency, significant trends have not been detected.  It doesn't mean that there is no a change, it just means change has not been detected (using current measures).  You can't make claims that something does not exist.  All you can say is that something has not been detected.

And yes, it is very good policy to try and mitigate climate change.  There are many reasons.  A few are that temperature increases provide significant challenges to ecosystems, biodiversity, human health and agricultural production. Loss of terrestrial ice and warming ocean water is already making a difference to sea levels and will continue to do so, with bad consequences across the world.