Wedding dinner songs about impending death

I can never understand why these two songs below are so popular among so-called "professional" singers or even karaoke singers during Chinese wedding functions here. Is it just because their melodies are so easy on the ears that they must be sung at all costs? Don't the lyrics mean anything to them at all? But more importantly, do these singers actually understand what they are singing?

Come on, these are weddings, the celebration of two lives tying the knot as one happy couple, and yet....the singers don't have anything better than to sing of death and impending doom. What can be more suay, what can be more pantang, what can be more depressing for the couple and their families to hear such fatalistic words, especially when the singers suddenly decide - on inspiration - to dedicate these songs to the happy couple??

Excerpts from Tom Jones' "Green Green Glass of Home":

Then I awake and look around me, at four grey walls that surround me
And I realise that I was only dreaming.
For there's a guard and there's a sad old padre
Arm in arm we'll walk at daybreak.
Again I touch the green, green grass of home.
Yes, they'll all come to see me in the shade of that old oak tree
As they lay me beneath the green, green grass of home.

Excerpts from the Bee Gees' "I Gotta Get a Message to You":

The preacher talked with me and he smiled
Said, Come and walk with me
Come and walk one more mile
.....
Now I'm crying but deep down inside
Well I did it to him
Now it's my turn to die
.....
I've just gotta get a message to you
Hold on, hold on
One more hour and my life will be through
Hold on, hold on