Rejected after interview for not having enough experience

I'm a recent college grad who's looking for a full time job. I've been sending out tons of applications, getting very little response, the whole dejecting works. Anyway, this recruiter I talked with recommends a lab job, it seems interesting so I apply and we get an interview set up.

I go to the interview in the evening and it seems to go really well. Maybe not perfect, but as close to it as my limited experience can get. The next morning, my recruiter talks to them, and they reject me by saying that they were looking for someone with 6 months experience in-field.

When I interviewed, they told me I was the first person they interviewed. Combined with how early the recruited talked with them, for certain no other candidates were interviewed after me and before the rejection.

So I'm just shocked and insulted. If they knew I wouldn't have the right experience, why waste my time with an interview? They absolutely could have looked at my resume and ruled me out immediately. It seems incredibly unprofessional to not have considered that beforehand.

Am I crazy? Is this common nowdays? Why don't employers consider the time investment to interview?

Pretty much ruined my day today.