I really don't get the vehemence of the people who found Hope's storyline believable. Just because it worked for you doesn't mean other people are lazy or greedy or in any way 'wrong' for finding it unsatisfactory.
Yes, Hank has every reason to not want her to be the Wasp. That's perfectly explained in the movie. The problem is that Hope has no reason to be perfectly ok with that, and yet she apparently is perfectly ok with it, and that is not explained anywhere at all.
Does Hank have a fatherly obligation to give her his suit? Of course not, though if she is the best person for the job and the stakes are really as high as he claims, he probably does have a moral obligation (to society) to do so. Even if he doesn't, the problem is still Hope's (complete lack of) reaction. Just because he isn't obligated to go along with her doesn't mean her natural response should be to just give in and not even try to convince him anymore.
Could she have stolen the suit and used it herself? The answer of course is whatever the writers wanted, she could do. There's certainly no reason given in the movie why she couldn't (yes, the suit was locked up - in her father's house that she knows like the back of her hand using technology she's probably very familiar with).
Could she need Hank's help to get it done, even if she had the suit? I'm really not sure how. Aside from certain bits of family history, Hope seemed to know just about everything Hank knew. She was good at controlling the ants, she was already familiar with the suit. What exactly does Hank bring to the table that's so important she couldn't possibly move without it?
Was she the best person for the job? That's open to interpretation, but my interpretation is: probably, yes. Scott may have the actual theft experience, but right up until the last minute (when Cross got suspicious and tripled security), the most important part of this job was using the suit and knowing the company/building.
Did she have to be standing next to Cross at the moment the theft happened? This is basically the strongest reason the movie gives for what happened, but it still doesn't really convince me. Sure her being late might make him suspicious, but would he really have time to alter his plans? And given the ultimate plan turned out to involve basically bombing the entire place, I don't see how her being in the suit would really change the plan at all.
In regards to Hank's 'character development', where the heck did it even come from? This is exactly why I would've loved to see this IN the movie, rather than tacked on as a mid credits scene, because we would've gotten some actual interaction and development between the characters, so that we could see that Hank finally understood that he couldn't stop Hope from following in her mother's footsteps just because he wanted to. Instead, we see absolutely no character moment and just skip to him giving her a suit with no context at all.
And as to people supposedly wanting everything 'right now', since when has it even been a question that a film should feel complete and believable on it's own without requiring you to watch a completely different movie years later? Not buying Hope's storyline has nothing to do with wanting everything 'right now', it has to do with not buying Hope's storyline. And the 'teaser for the future' argument doesn't even make much sense, considering nobody's really sure if there even is going to be an Ant-Man 2 and Marvel as of yet claims to still have no idea when Hope (ie, in which movie) will actually make her debut as the Wasp.
