Are you honestly suggesting that people hearing recorded announcements are intimidated and unwelcome? How, therefore, do these sensitive people manage with airport security? How do they manage at a concert/gig where bags are routinely searched or football where people are routinely searched? These are much more intrusive and disruptive security measures. Do the people you think are scared by recorded announcements simply not leave home and lock themselves in a cellar for safety?
I think you're missing a key point here. In all of your examples, security checking is done by
another human being, who should be and usually is a professionally trained security operative. When I go to a bar, rugby match, gig or airport I expect to be searched, and well trained security staff will project the situation something along the lines of "sorry, we need to do this, you're not suspicious but would you mind awfully showing us inside your bag?" I can make eye contact with them, ascertain a certain level of trust man-to-man (or woman) and establish that we have a mutual interest in making the process as painless as possible.
By profession I'm a datacomms/ICT engineer so regularly carry work tools that could be used as offensive weapons, but so far have never been denied entry to bars while carrying my work bag - a few questions but once I explain what I do for a living I've never had a problem.
This is completely different to an impersonal, robotic-sounding voice over the PA telling us every 30 seconds implying that the environment we are in is unsafe, full of terrorists and we need to be so suspicious of fellow passengers in case they're going to blow us up.
Agreed with
CaptainHaddock that this has the potential to discourage use of the railway if not familiar with it, and certainly doesn't give a good impression of our country for visiting tourists, and for commuters the daily repetition just causes tune-out.
* there are some security personnel who act like jumped up wannabe Stasi agents, but thankfully in my experience they're in a small minority.