the size of the raid makes a big deal of the appearance
I never liked the idea of the same raid with both 10m and 25m
the biggest reason is how do justify that it takes 25man to down the Lichking and well you can do it in 10man also ???

but the biggest concern is the healer/tank ratio i whould love to
have them at a 1/5 ratio each meaning
in a 10man 2tanks 6dps 2 healers, 25man 5tanks 5 healers 15dps

yes 25man whould it be posible to switch around to 4tanks 6healers 15dps but i don't like the layout of today 3tank 6healers 16dps it means tanks is less in demand in the end.

Why not just design some raids around 10 and some around 25, and then let people switch them to either size?

"Why not just design some raids around 10 and some around 25, and then let people switch them to either size?"

To me, that seems like what they already did...

Sure, Ulduar is huge and therefore appears like it should have a lot more people in it. But ICC, on the other hand looks to me like a lot of rooms were designed with 10 people in mind. As someone mentioned above, Deathbringer's Rise in particular seems cramped enough with just 10 people spreading out.

They can just continue to alternate huge rooms and cramped rooms and then institute a new secondary profession -- Gnomish Therapist -- so that we can all learn to deal with the OCD that is bound to arise from our constantly alternating feelings of claustrophobia and agoraphobia.

Gnomish therapist . . . I love it! Then they can make these:

Gnomish Tissues
Item Level 1
Use: Cures QQ. May not function properly when used on another player.