A competent developer would be more likely to send a PR using the tool with zero friction than to dedicate a few additional hours of his life to create an account and figure out how to use some obscure.
You are making the same mistake of conflating competence and (lack of) dedication.
Most likely, dedication says little about competence, and vice versa. If you do not want to use the tools available to get something done and rather not do the task instead, what does that say about your competence?
I'm not in a position to know or judge this, but I could see how dedication could be a useful proxy for the expected quality a PR and the interaction that will go with it, which could be useful for popular open source projects. Not saying that's necessarily true, just that it's worth considering some maintainers might have anecdotal experiences along that line.
You are making the same mistake of conflating competence and (lack of) dedication.
Most likely, dedication says little about competence, and vice versa. If you do not want to use the tools available to get something done and rather not do the task instead, what does that say about your competence?
I'm not in a position to know or judge this, but I could see how dedication could be a useful proxy for the expected quality a PR and the interaction that will go with it, which could be useful for popular open source projects. Not saying that's necessarily true, just that it's worth considering some maintainers might have anecdotal experiences along that line.