I think something like that would annoy a lot of users, facing someone who is very fast and can run from one area to another in no time. With unlimited speed, you wouldn't 'waste' your speed by dashing and you don't even have to wall climb, it's more than enough for you to run and wall run. In TDMs, your enemies wouldn't even be able to med properly because you can show up in no time, doesn't sound fun to me.
