I think a number of people are worried about Apple shooting themselves in the foot, or screwing their customers. Apple's handling of software development in the '80s almost killed them. Microsoft's 'steal it, pirate it, just develop for it' mantra got us to where we are today.
Apples default of signed programs is probably best for consumer safety, but many times the best ideas don't win the market.
Perhaps, but to be honest until Apple does something entirely crazy I think the worry is premature. Microsoft had more than the "do what you want with it" mantra, their lockin to any pc hardware was more valuable. Additionally 80's Apple isn't much of a parallel to today, the company is not at all the same.
The signed binary stuff has been in OSX since around 10.4, so to think this is a recent action by Apple is somewhat wrong.
Apples default of signed programs is probably best for consumer safety, but many times the best ideas don't win the market.