The right mindset would I think be to show them that they were wrong if they reject you.
Ultimately fundraising is selling. And in sales, your goal should, funnily enough, be to get as many rejections as possible. To eat "no" for breakfast, as it were.
Easier said than done, I know.
When you are building and selling a product, shifting your focus to fundraising in the middle (and not committing to it) is stupidity and would leave you to neither be able to build/sell well or fundraise well. It's a mindset shift, and one of PG's essays talk about that too.
Problem is not with rejection. Rejection from the customers is what motivates people. I am not motivated by "wanting to show others they are wrong", but by solving a problem, creating value, and impacting people. What you wrote is a weak justification for the time you spent on application - that could have spent on building product or a sales pitch.
Again, my point is not rejection but distraction. It's about focus. When you are in the middle of building, it's unhelpful to just fill out an application for "what if". Don't do it. Most entrepreneurs know when they are fundable.