Yes, I do feel bad for using apps like this, but I have no other legal and affordable choice. I have Fetch TV which offers movies and additional content bundled with my Internet connection, you get 30 free movies per month (usually older movies) and have to pay for newer ones which can quickly add up if you pay for a few of them.
Popcorn highlights a real problem in the entertainment industry and as someone who's looked into starting a Netflix like service in Australia, the licencing and costs associated with licences and obtaining decent content are way too expensive to even consider starting something up.
Until the situation improves for us Australians and our New Zealand neighbours amongst other countries, people will continue to use apps like this. Learn from Spotify industry heavyweights and open up your content for streaming globally via paid services like Netflix.