Nice politics of Blizzard, 45 maps (as mininum 100 hours per map, top quality can take 500-1000 hours). Suppose about 7k hours spent on 45 maps. About 50 maps eliminated ~ +4500 hours. Totally about 12k hours of programmers. Free maps for arcade SC2. Imagine how much they should pay programmers inside Blizzard. They receive as minimum 5k$ per month(some of them may be 10k, one month 160 work hours.) 12k hours / 160 = 75 months. So cost of all these maps about 375 000$ - 750 000$. Nice work for free. And it's just work for several months. Total cost of all arcade maps for 5 years ~ several millions of $$$.(or even much more)
I spent myself over 100 hours on WC3 Castle Fight for this contest. And noone played this, it was my fault because other devs published other version of Castle Fight one month before mine(facepalm). Still can't believe that they developed same map(T_T).
Also remember that all maps and stuff are property of Blizzard Entertainment under the agreement, which was created by them. So even we are original creators of maps we can't even do anything. We are just giving our works for free.