Yes, that's an important reason to keep in mind. I've had players strong enough to know better argue for putting their pawns on the same color as their bishop in an endgame, but mobility and giving up half the board as you said are clear reasons this is (generally) wrong.
The true meaning of "Bad Bishop"!
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Yeah, that's why I said it's generally wrong ( not all the time).
But this one guy was telling me his "theory" about bishop endgames, and how it's always a good thing to do 
I gave up trying to talk him out of it... he did eventually agree later.
A lot of people think a "Bad Bishop" is one that is impeded by it's own pawns (because they're on the same colour) but it isn't!!!
According to what I read somewhere a "Bad Bishop" is a bishop for which the pawns are on the same colour, but the reason why it's bad is not because it will be impeded!
The reason it's bad is because with the bishop and the pawns on the same colour they only control half the board so what going to defend the other half. (it's bad when its a lone bishop i.e hat makes it bad is the fact that is partner is not there to protect the other colour)
a good bishop controls one colour while the pawns control the other. that's why it's good.
this means that what makes a bishop bad is the "weakness of squares it doesn't control" and this creates two more terms:
Good "Bad Bishop"
If a bad bishop is not impeded by it's pawns then it's a good bad bishop
Bad "Good Bishop"
If a good bishop has difficulties in one small area
A Good "Bad Bishop" has unrivaled power on half the board it becomes very powerful
but a Bad "Good Bishop" the power is distrbuted over the whole board so it's power is "dluted" (a Good "Bad Bishop" is concentrated)
and since it has dificulties in a small area it lowers the strength.
therefore:
A Good Bad Bishop is better than a Bad Good Bishop
(if that makes sense:D)