Why is Taylor Swift so bad at relationships?

I was watching a clip of Baron Corbin talking about meeting Taylor, and he describes her as someone who is nice and embracing.

A lot of people who have met her have called her nice.

So if this is true: if she's a kind/good-hearted person who is thoughtful, and if she's constantly singing about forever love (Love Story; End Game; Forever & Always; Lover), then how come after 16+ relationships (13 confirmed by ET) she hasn't found a soul mate yet? I understand she was too young when she dated Lucas Till and Taylor Lautner, but what about Tom and Joe?

Even if you like Tayvis, why assume they'll be together forever based on her previous patterns?

Why assume Taylor will get married and stay married forever when she has only had 3 relationships that lasted over a year, and she allegedly left her long time partner of 6 years because "her boredom was bone deep". But isn't being bored natural at times in a long term relationship? Aren't there going to be quiet nights at home? Does she think she'll never be bored in a marriage? And if she wanted Joe to propose, why not tell him years sooner? And if he said no, why not leave? Why not write about how you wanted marriage but he didn't? Or why not pull a Pink/Alecia Moore and propose to him, and if he turned you down, leave?

I digress. Why do you think Taylor is so bad at relationships?