You know aikido and ukemi are two sides of the same coin, resisting to failure of nage's technique doesn't always make friends and can deprive you of an opportunity to learn the second half of the art in kata form. I'm not saying resisting isn't appropriate in training, but needs to be tempered so the the nage-uke dynamic is productive experience for both. YMMV and it perhaps it has.
FWIW when I encounter just an uke who resists to failure all the time, such that the practice becomes unproductive, I just become uke for the rest of the session and work on my ukemi instead, so at least I can learn something and the time isn't wasted.
PS Have you considered that you may appear to be the bully and this is a way for the 'protagonist' to deal with it?
Thanks for the help! You mean, I'm being the bully by working hard? I haven't said anything negative to him, so I don't know how I could be a bully.