Whatever the reason, this (coasting onto stand) is a stupid and extremely unprofessional thing to do.
Sadly, extreme fuel saving (if that's what this is being done for) is a particularly beguiling genie which has been let out and can never be put back.
Owing to the fact that fuel saved can be projected by multiplying by the number of sectors flown per year, even a 10kg saving can be made to look like say, 200,000kg per year. Fuel costs $1 per kilo, so abracadabra! you've "saved" $200,000!
This is a classic demonstration of how statistics can be manipulated to show whatever you want them to. Because you haven't saved $200,000, you've saved $10. But it has led to all airlines single engine taxying, not turning all the aircon packs on, not having aircon on at all while on stand, and not putting on the heating/cooling before the passengers start getting on - leaving the cabin crews to work in awful conditions, and other stupidities.
As an illustration of how far this could go; why not turn off one engine at the top of descent? I mean, you're going down anyway aren't you? Then at say 10,000 feet, fire it up again for the landing.
Don't laugh, this sort of thing could happen.
The way round this of course would be to charge the proper ticket price for the flight
