You didn't say you didn't like it, but, you said it was poorly made. "Poorly made" can be qualified, "I didn't like it/find it scary" is an opinion.
It sucks you didn't feel anything -- but that doesn't necessarily mean it's poorly made. I can find plenty of people who think Alien isn't the least bit scary.
(For the record I'm not trying to say you're wrong for not liking it, and I'm not saying you're wrong for thinking it's poorly made, but it feels like you're saying you don't think it's well made because you don't like it, not because of any actual critique of the filmmaking. I was just genuinely curious to hear what you felt fell flat with the actual filmmaking.)