As a contrast there's a scene where Ismay is walking though the deck and they are all glaring at him which clearly DOES show that he feels guilty, the passengers blame him, and we the viewers are supposed to agree.
The newspapers, spearheaded by Randolph Hearst, were gunning for Ismay before Carpathia even docked in the US. He sent a flurry of telegrams to his parent companies, begging that they hold the White Star Line ship Cedric until the Friday morning so Titanic's crew could be returned to the UK and thus talk less to the media. The bosses weren't having any of it.
Because Titanic was technically owned by J P Morgan and operated under International Mercantile Marine that placed her under US jurisdiction. The US Senator William Smith was strongly opposed to Morgan interests, and set out to to establish evidence of negligence by Titanic's owner and operators. If Ismay was concealing any such knowledge the IMM could have been sued. Smith was appointed as leader of the US-based inquiry - Ismay and the surviving officers were not allowed to leave the US until it was complete - and hoped to achieve that result, both for his American constituents and as a matter of political grievance.
So Ismay had come up against two very powerful enemies in the shape of Hearst (the film Citizen Kane detailed his life and pretty cutthroat practices) and Smith.
The inquiry ultimately exonerated him, along with Harland and Wolff, the ship's builders, but excoriated Stanley Lord who was captain of the Californian.
After Ismay returned home, he then had to face the whole process all over again in a UK inquiry, which also exonerated him. But by then Trial By Media was complete and the damage had been done. By all accounts it left him completely broken.
The media also went after the Marconi operator, Harold Bride, because he gave one interview to the papers. This was totally unfair: from what I understand, the man was a hero. Even with broken and frostbitten feet, he assisted with the wireless operations on Carpathia to send through lists of survivors, and didn't stop working until he collapsed and was admitted to hospital in New York.