Makes you wonder if Captain Philpotts was a man full of grit during this time or if he was a young man that just finished officer school
Captain E.M. Phillpotts was 43 at the time of Warspite's commissioning (March 1915); he had been a naval officer for 24 years by that point, and had held the rank of captain for the last nine. Warspite was his fourth command, if you don't count a brief stint as acting flag captain of HMS Bulwark before he was promoted to captain.
Then as now, inexperienced men were rarely if ever placed in command of capital ships, and particularly not as the commissioning captains of the most modern ones. Naval cultures have long prioritized seniority in such matters, and generally still do. Back in those days, junior officers might command much smaller vessels (WWI and WWII submarines often had lieutenants serving as captain, for instance), but certainly not the largest and most powerful ones, with the most numerous crews to manage.