I agree that's americanizing, but in the sense of taking every single precaution so that nobody can sue you ...
More seriously, some chaps in the quality/safety management services have suddenly figured out that the word "maintain" might prevent some level busts... so here we go ! now we have to use it ! or at least we're advised to use it... but would the word "advised" make any difference in case of accident ?
Now, another example of some great thinking: a plane has been cleared on delivery on some std departure up to level XX. Now at first contact, we're advised to say "maintain level XX on reaching, I'll call you back for higher" and not to use "climb" if not giving further climb...
I agree that safety is a serious issue, but if you consider every single little possibility of a misunderstanding or of a mistake, you'll end up making 5 minutes sentences as clearances... Are you supposed to make the rules for one stupid fool ?
And now let's imagine that you have eradicated any possibility of misunderstanding in the language, now what happens if the pilot selects level XX plus or minus 10 instead of XX and still reads back correctly, because he's thinking about the cute steward/stewardess that just brought her/him lunch... Will we ask to have the selected level on our screen through S mode radar ? And what if the controller makes a mistake, will we ask to have two ATCs on a position so that the second controller can check on the first one ? And maybe a third one, to check on the second ...?
In my unit, we used to have some level busts problems with a circling approach with departures climbing 1500ft and arrivals in opposite direction descending 2500ft. Guess what the management suggested ? That there should be one more controller on the Vcr looking at the radar screen to see if those two levels were maintained correctly...
We're living in an unperfect world, and we're only humans, and we've to cope with it every day!
So now, I'll use that phraseology, but please don't add more because some guy in a well heated office has decided that to cover up his ass he'll invent some new and revolutionnary way of preventing accidents by adding something .
Oh and by the way, I'm not working in The UK, but in France... Looks like it's now spreading...