Spending big $$$$ on low visibility items such as an effective preventative maintenance program for your explosives detection instruments is not going to happen. Tens, maybe hundreds of thousands of new uniforms can be bought with those $$$$.
Puffers are still in production because other industries use them and have made them work effectively and reliably.

And while we're talking of not thinking things through; if WBI cannot image through adult diapers, colostomy bags, etc. then TSA will either have to
1) subject pax with those items (and the item) to hand search scrutiny or
2) will have to largely ignore those pax showing that image block.

If the course is 1), even TSA will not be able to ignore the outcry as it becomes apparent to all who is "equipped" with items that they really don't want the world to know about.
if 2) then WBI is an expensive, intrusive annoyance with less than zero security improvement

Seems to me the only reason WBI would be viewed as a better security asset than a puffer is if the bottle of water in a pax cargo pant pocket is perceived as a bigger threat than a pax with traces of explosives on their person. Sadly, it seems many in TSA are that delusionary paranoid about simple bottles of water.