Has anyone else ever thought this way?
Yes. People have argued for that many times at p5p. But p5p is (IMO rightly so), extremely careful not to break their customers (that is, anyone using perl5) code by doing a simple upgrade.
If you make strictness a default, code will break. That gives a lot of negative karma for Perl. It's decided it's not worth it.
Oh, and if you argue "but adding no strict; isn't that much work", then I counteract with use strict; is only one character more - so, it's not much work, is it?