Why now Doctor Who promote Lesbians and gay and bisexual ppl ?

that tiny amount of people are unwanted anyway

Am I in a time warp? It was executive produced by a gay man since 2005. The male Doctor has kissed a handful of men.

Because it's okay to promote them. Who cares if they lose viewers, they're doing the right thing, and I wouldn't want idiotic homophobes watching my show anyway.

Because of sexual diversity. Doctor Who also promotes straight ppl, so why not?

After "The Timeless Children" mess destroyed Who backstory and rewrote it, sending fans scurrying to the internet to proclaim their anger, I hardly think a few gay people are sending people running from the series. 

The new Dr Who has long been accepting of sexual orientations (remember Capt Jack, who spun off into his own series, was bisexual and played by a gay man).

"Don't they know they are losing viewers for that?"

Unlike you, most people appreciate diversity.

People like you also complained about Star Trek back in the 60's for having a Black woman, a Russian, a Japanese character and a Vulcan (who appeared to look devilish). And yet Star Trek became one of the most beloved TV series in history.

It's all about filling quotas, all minorities must be included regardless of how distasteful they may be.