Yup, we don't need fast floating point - this just acting as an RMQ provider for some analog sensors.
What we do need are boards with much better manufacturing QA/QC than Raspberry Pi. After the nth time the USB 5V falls out, or the SD reader loses contact, you rapidly realize they're not targeted towards a production environment. As inexpensive and powerful as possible is a great goal, but you invariably lose some reliability ("pick two").
Some integer code might run at comparable speed.