Junction 8 Why?

I live in Lenham and I have to use Junction 8, I do not understand why they modify junction 8 in any way. The queuing traffic never gets back that far, you could leave 8 as a normal 3-lane intersection and make modifications after the junction. I have seen many close calls where lorries suddenly change lanes at the last minute to continue on down the motorway, it makes no sense to me whatsoever, change the junction back to normal and reopen the sliproad coastbound.