One complaint? No. But hopefully a series of complaints would. Airlines are always saying there are way more applicants to become an FA than there are available positions, so as long as that holds true there's always someone willing, it's just a matter of training.
When asking in situations like this, I always start with "Would it be possible to..." or something along those lines, it seems to de-escalate before it could even escalate, and usually helps in getting what I want/need. Especially trying to check in early to a hotel, I've never had an issue.
Agreed, sometimes you need to do the "pretty please" approach, annoying as that may be. As far as large number of applicants, true, but some of the new generation isn't exactly world ready. Not that everyone in my generation was but this is a different level. Not to mention recruiters are under considerable pressure to fill "x" number of jobs in "x" days. Accordingly, if someone looks half way presentable and can make it to interview on time that's saying something.