Do churches "water down" the Word? I am sure there are some that do, but they will be held accountable for what the have "taken away" from the truth. However, how many churches are losing new potential members because the message they present cannot be related to the situations that people face today?
You have every right to have this opinion, but I disagree. Evidence shows the contrary. Biblical truths are timeless and do not change for a generational "fit". Once that attempt is undertaken, trouble begins.
I am linking a very interesting article that thoroughly discusses many of the misconceptions of the updating you allude to. The article happens to apply to LCMS, but I'm sure you can change the name and apply it to other denominations as well.
THIS is a worthwhile read if the topic interests you.