Beside the advice to write about what you know, the other suggestion for undecided writers seems to be to write in the genre you enjoy reading.
While you can't currently go back in time, you can learn about and experience the past in the here and now.
So I can see the logic of the latter. Every writer needs to read within their genre, so they know the requirements of that category, what's had it's time in the spotlight, and other developments.
While I prefer to write historicals, I'm quite happy to read contemporary, or futuristic. I'll even read fantasy- charming vampires, and werewolves.
(But like any book, if the basic plot idea doesn't appeal to me...)
I've experimented with my writing as I've learnt, but no matter when or where I set the story there was always a romance involved.
As a teenager I wrote a romantic saga set in space- there was even a prequel about the parents of my hero. But that didn't have a happy ending- the father died in an air crash during a snow storm...
I can still remember elements of that saga- the hero and heroine's long marriage, numerous children and grandchildren (some were even part alien), but I never kept the hand-written pages. And as I was a bit vague on the scientific theory of futuristic space travel, perhaps it wasn't quite the category for me forty years ago.
Then there's contemporary. I enjoy romances set amidst a mystery or crime- as long as any murders included aren't gruesome, in fact if they are involved then I prefer the murder off the page. I don't want to actually read about it as it happens.
I've always loved history. I'm lucky my family don't mind the occasional trip to historic buildings and places wherever we are on holiday, but too many and I have to go by myself...
Perhaps I've trained my brain to see my characters in an historical setting? They certainly appear in costume; well usually, apart from a character I started developing when I attended Sally Quilford's pocket novel workshop last October. :-)
I have a couple of contemporary characters who popped in last weekend, 'Hal' and his lady- who I discovered is wearing that red and yellow corset I mentioned recently- and why.
I will probably have a use for them when I do the Kate Walker workshop in May.
(If you know of anyone who might be interested and can get to Nottingham on the 19th May, please pass the workshop details on, there are places still available, and it's very affordable.)
Perhaps in the future I'll be able to create contemporary characters, but at the moment the historicals continue to dominate.