This is a very wild guess, but I recall there being some resentment towards Polish immigrants in the UK on the basis of "they took our jerbs!", especially ones working in utilities. So my thought was that this could be a in a small way an attempt to counterbalance this characterisation. See? Polish repairmen are cool!

Of course, the whole thing was a long time ago, long before brexit, the girl tweeting this may not even be from the UK, etc etc. But there could be a reason along these lines, who knows?