In my mind it has to help the clean, I've run out of gas while working in past and instantly noticed the glide get slightly harder on the glass and little marks on frames sills etc need that extra pass.
I look at like this for example, next time you butter a piece of toast shove the knife under a tap of cold water and watch the left over butter on the blade, nothing shifts then put the hot water on and watch it run off into the sink.
No scrubbing or anything just a change in water temp, now we don't have butter on windows lol but its just a point that it helps soften any dirt,bird crap or anything else on the windows.
I love the soft hoses too,makes dragging them round just that bit easier and yes I could and have worked with cold and it wouldn't be a problem but anything to make the job easier or better for me.
I use the cheaper stainless heater myself and its well set up,vented efficiently and maintained every year and this is my 4th year now and its still going strong, they are made very cheaply though having stripped it down in past and it will always be a risk but for me no more than an electrical wire burning out etc because I have it set up fine and serviced every so often.
£30 a month on a 19kg bottle I spend and always shut it off when finished at the end of the day, maybe I could put an inline tap to easier shut it off after every job but I'm happy how it's set up, can understand others concerns though but we all do our own things in life.