Beer served at room temperature would be sent back in the UK too. As stated above, bitter/ale is served at cellar temperature (around 12C/54F). Lager is, of course, served chilled (although perhaps a degree or two less chilled than you might find it in America).
Oh but they can! Tea bags, regardless of what the snobs say, can produce a perfectly good cup of tea - but, like leaf tea, you have to use boiling water, as in proper, fresh-out-of-the-kettle-just-as-it-clicks-off boiling.
Putting hottish water in a cold cup in a hotel kitchen, then putting it on a saucer with a wrapped tea bag on the side, then carrying it out to the customer thus letting it cool down even more before the tea bag is even put into the water, does not result in a good cup of tea.