Sure, SaaS is a good model for some things. It certainly does have that nice feature of being unpiratable. That makes sense of course... in SaaS you aren't selling a digital copy that is fundamentally worthless. You are selling computing power, updates, support... stuff you don't need bunch of arcane laws to protect!
As copyright laws ease, some will turn to SaaS, but others will embrace the model of letting a lot of people have something for free, and charging those that can afford it.
Heck, people like to give books as an example of media that must be protected and that will never be free. But guess what... the most popular Kindle authors these days give many books away for free.
Moreover, the biggest companies have been turning a blind eye to piracy because they believe it helps them sell more software, for ages. Microsoft is the biggest example... as Bill Gates once said (and I paraphrase) - I'd rather you steal my software than buy my competitor's.