It's nice to provide some continuity for England's squad through the winter.
They've had one promising Yorkshire cricketer waste three months of his life carrying drinks around in South Africa, so they may as well have another one doing the same in Bangladesh.
If the reason for not taking Rashid to Bangladesh is because he hasn't bowled enough, how much bowling has Tredwell done in the last 2-3 months? It's a horsesh*t excuse IMO.
As for the captain deciding he can't be bothered (that's effectively what it is, don't swallow the BS coming out of Geoff Miller about him being "rested") he can count himself lucky that there isn't another strong captaincy candidate around or I would have taken it off him. It should be the biggest honour for any English cricketer, and to opt out of doing it because you don't fancy a trip to the sub-continent is a disgrace.
I can honestly see England being lucky not to lose in Bangladesh if the ECB are basically allowing players to pick and choose whether they can be bothered. It just sets a completely negative tone for the whole trip from the kick-off, and anyone who has watched Bangladesh against India this week will see they're not a bad side by any stretch of the imagination.