As someone who has been on the inside (Ricky Lee workshopper, writer for ABS-CBN), that is the case. The networks, by and large, make programs that are guaranteed to be hits because these days, the ads don't support the shows, they make the shows so you can watch the ads.
It's not because we lack writers with original ideas. I know A LOT of writers who have EXCELLENT, ORIGINAL, EXCITING ideas for shows (not to brag but yours truly included) but the networks want guaranteed ad revenue. Even if by some miracle your original idea was approved, you will be asked to rewrite it and rewrite it and rewrite it, until it becomes MORE generic and only the shell is left. It's so much so that Ricky Lee has told us that if we manage to get one or two original/new twists and turns into the soaps we're writing, it's considered a triumph for us.
Writers have almost zero power in writing these shows. And they're poorly paid too. I know writers who'd work well into the wee hours for only FOOD and a thank you.
So if you watch a Pinoy telenovela and you notice all of these tropes, it's NOT because of the writers. It's because of the TV network executives and advertisers who want GUARANTEED ratings (i.e. nothing so new that it would risk turning off viewers) and the Pinoys who swallow it all up in big numbers.