Indeed there is no shortage of options for security if you need it. The church in fact has security guards around some of its facilities here at their world headquarters (where I live) but they don't appear armed. And I've never seen any overt security guards at any of their worship spaces.
I can see why the initial policy would be that worship spaces are a no-weapons zone. Every church wants their space to be simultaneously inviting and safe. The visible presence of weapons might ruin that for some people. But the focus has shifted. Once the tragedy, the illusion of inherent safety is destroyed.
The standard American "good guy with a gun" argument is rarely well thought out. Nobody really knows how it's supposed to work because it really doesn't work out very often. If there was a foolproof way of distinguishing the good guys with guns from the nut jobs with guns, then we'd have something that worked. Other countries solve that problem by paying less attention to the good-guy / nut-job dichotomy and focusing more on the with-gun / without-gun distinction.
Here it comes down to the notion among many Americans that the 2nd Amendment makes them (not the state) principally responsible for their own safety. You are permitted to own a gun with little restrictions for your own protection, including against nut jobs. And if the nut jobs are going to start showing up to church, you should be permitted to carry your weapon there in order to extend that protection to that space.
It could be that the guards were armed but it was not obvious.
For example...
I once had a lunch where I ended up sitting at a table with three female detectives.
They were all wearing 'business suits' and one was teased/criticised for not 'wearing' her firearm.
(The others were assuming that she had it concealed in a bag.)
She laughed and moved her jacket, revealing the standard police automatic.
(In a 'shoulder holster' on her left hand side.)
She then started handing out business cards for the tailor, that had tailored the jacket to hide the firearm.
The other two were quite impressed with the result.
It was a bit of an experience for me.
The three women were young, intelligent, witty, well dressed, obviously healthy and physically fit.
I've never felt safer in my life.
(Even though they made the standard 'joke' that I'd heard many times before: "If the ◊◊◊◊ does down, we're hiding behind
you.")
