I don’t think creating martyrs at this time is a wise political choice
There are many on the scene who totally agree with you. The see the surrender as a ploy by Lopez, an ill-advised ploy, to place himself at the head of the opposition, especially since what some are now calling the "19F" insurrection, or movement, seems not to have arisen from any organized effort by the recognized, legal opponents of the regime.
It is also thought ill-advised if the regime is at crossroads where it's continued existence requires a Cuba-crackdown. Lopez could find himself on "The Isle" for a very long time.
Some thought he did not believe he would actually be arrested. But, rumors abound when there is little credible news.