You can get to work some quicker way and run instead. Running is much more valuable than walking.
In any case, I do ~6 hrs of martial arts per week, and I find that walking is a nice low-impact type of activity to complement it.
Also I have bad knees that make even the mile I walked to the job I just quit a little difficult. I doubt they will ever heal enough that running is a good idea.
If showering is not an option, choosing the right apparel can get you through the day. http://shop.outlier.cc/index.html
The compromises are an inconvenience, but IMO the subsequent healthier and happier life is worth it.