I actually enjoy a good soap death sometimes. When written well and given the full impact on the characters left behind it can be some of soaps best emotive drama. On the other hand they have to be spread out well and planned down to the last detail or they become very stale and everyday. Hollyoaks get get a lot of (rightly so) criticism for the way they brutally dispatch characters one episode and completely erase any trace of them in the next episode. In these cases it does become very pointless and blinkered as far as the characters are concerned. The majority of them could return at some point as they still have bags of storyline potential and under different writers/producers could have thrived but now we're left with 'what if' and a degree of frustration.
Killing a character off shouldn't be taken lightly, but at the same time they shouldn't keep characters alive on the off chance they may one day chose to return. Hollyoaks (sorry i am picking on them a bit) chickened out of killing off Brendan Brady and i think even fans of the character agree it was probably not worth it for the lame exit he ended up with just in case by some miracle he wanted to return. Sometimes killing a character off is the only way to realistically say goodbye to a character and in grief it opens a lot of storyline opportunities for the characters left behind.
British soaps are known for being 'grittier' and more rooted in realism than American soaps. Although the soaps can be OTT and sometimes downright bizarre they are more supposed to be an exaggerated version of real life melodramas whereas i think American soaps prefer the more almost fantasy elements of soaps. Thats one of the reasons people don't really like recasts in soaps much. Its fine for one or two characters (or mainly children) but to remain that element of realism the actors are usually associated with 'their' roles that it can be very unsettling to see someone else (no matter how good) in the role. Obviously its on a character by character basis but usually if they can't get the original actor back they'll just scrap plans to bring the character back or work around their absence some other way. It does cause problems for big events like weddings, funerals etc but its usually just easier not to mention why 'so and so' didn't come.
A soap death also breaks up the normality of characters leaving in a taxi/train which can become very repetative with the turnover in British soaps. Neighbours use the same 'leaving in a yellow taxi waving out the window to friends/family' exit quite a lot and while its nice to see characters leave happily/alive it can also become a bit stagnant and dull almost like being given the same exit scripts of another character just with their name crossed out and yours put in there which must be a bit disappointing. Sometimes an exit has to be a bit more final and exciting than moving away for a new job.
Murder is used to much as an exit though. People do die other ways than being bludgeoned/shot/stabbed. I always prefer a death to be emotional, character lead drama. When a murders brought into it it becomes very tedious with the police never getting the right person and the storyline always becomes less about the person who died and more about the person who did it/didn't do it.