Strongly disagree. Most of the services, especially if you're a "catch" for them will go a long way to let you explore your interests on behalf of the country, whether that's a PhD program in an area with national defense implications (most of them) or testing new equipment. A "prison sentence" gives a great disservice to those who are adrift and choose to serve.

(Needless to say, the financial/educational benefits due to the updated GI bill are also quite attractive)