Same here. I believe this is due to will power depletion (plenty of studies conclude that will power is finite resource) and after our normal 9-5 drains away our will power, people have a heard time being self-motivated - very true for me at least.
Sure, if the things you're doing before work require willpower to pursue. They don't have to be. And jriot's point in my sibling comment is in any case well made.
I do this and just front load my day to have the more demanding stuff in the morning with the less demanding in the afternoon. It works well for me and if anything I feel my productivity has increased.
