Hindsight is a wonderful thing.
There is no doubt that at the time of its design and construction, Titanic was the finest example of design and construction afloat.
It is impossible to have foreseen the catastrophic effects of the iceberg's impact, and that in itself was compounded by the captain's decision to attempt not only to slow down, but to try and pass the berg, both of which added to the horrendous physical damage suffered by the ship, and its consequent rapid flooding and sinking.
The amount of portholes had absolutely no effect on the ship's sinking, that was caused entirely by the design which allowed water to flood over the tops of structural compartments, which rapidly dropped the bows below the waterline, and even more quickly upended the ship which broke her back and sent her to the bottom.
Not sure who your 'conspiracy people' are, but a quick lesson in basic ship design, coupled with basic physics, will show you that porthole inclusion was not connected to the sinking of the Titanic.