DSM - it is his business, noone has the 'right' to be served alcohol, he is fully within his rights to refuse service to anyone for any reason.
And if he, personally, believes that it is wrong to drink a pint and a half when pregnant, then in his bar, where he holds the license, he is perfectly entitled to do so.
TBH it is shocking that a paper would make someone out to be the bad guy when there are laws in place specifically to allow him these decisions. Whether or not one agrees morally is irrelevant. The law, is the law.
Imagine if the story had been different.
Imagine if the landlord had continued to serve the pregnant lady, so as not to 'humiliate' her. Imagine she had a few drinks, and something happened to her.
This poor chap would be slaughtered for selling her alcohol when she was pregnant. And he would lose his license.
He is completely within his rights not to serve anyone he does not want to.
And she wasn't asked to leave until another member of her party broke the law.