It didn't get the same attention because it had already happened, it was terrible, and nobody said otherwise, but there was no mystery or suspense about those peoples' fates. There was no ongoing story.
The Titan story is in the same vein as when workers get trapped in a mine for weeks, or like those children in a cave in Thailand. They weren't billionaires, yet the whole world still rallied behind them.
Also, to the columnist lady: you work for The fucking Guardian, if you felt that the migrant shipwreck story deserved more attention, why didn't you write about it then? I guess selling Western guilt gets more clicks huh?
I'd take this argument more seriously if the shipwreck wasn't ALWAYS mentioned in relation to the Oceangate story. I haven't seen a major news outlet discuss it on its own, nor do they report on other migrant tragedies ever.
Mentioning this tragedy only to make a point about media coverage is pretty shitty IMO.
I would add to this that, to most people, being trapped in a lost submarine and slowly running out of oxygen in the cold, dark depths is more horrifying a prospect than drowning. Both are horrifying, but one much, much more so.