Ten Is The Lowliest Number

AITOOW doesn't understand why politicians have resorted to a callow rhetorical trick of calculating the cost of something over ten years when they want to prove a point? Why is ten the new magic number? Why not 100 or 5 or 20? It totally distorts the true cost and reasoned discourse. Either inflating the cost for something they don't want (tax cuts) or reducing it to something they do (health insurance). All based on questionable premises. It's totally irresponsible and obfuscating.