The Glock is a good weapon for people who do not train with weapons regularly. The P35 is a SUPERB weapon for people who know how to use it. The 9mm caliber is vastly inferior to the 45 ACP, but IS adaquate. Also, the military has always had the heebie-jeebies about “cocked and locked” (as John Moses Browning INTENDED). I have clear memories of junior officers pawing at my M9 in my issue shoulder holster trying to place MY safety on “safe” (empty weapon secured in MY issue rig - yes the M9 is a SA/DA weapon - different entirely from the P35, but 100% safe carried with one in the chamber, safety off, ready to fire in the DA mode). I often asked the commissioned junior officers if they routinely snatched empty M16s (on which the safety CANNOT be placed on “safe” with the hammer down with an empty [or loaded] chamber). I got the deer in the headlights look, followed by a condescending bunch of commissioned BS. As a 1SG, I’d laugh and return my weapon to the condition that I wanted it in and carry on about my business. Point is - just like at Fort Hood, the politically correct BS is the driving thing. I love the Hi-Power. The Glock? A servicable, somewhat non-durable plastic pistol for non-shooters.
Glock; plastic frame, stamped parts, welded slide - a nonpermanent, disposable weapon.
Browning P35; All milled steel quality, robust design, absolute reliability, designed to last centuries.
Never settle for cheap stuff when your life depends on it.
It is somewhat similar to unarmed combat training. Most soldiers will not spent most of their time in hand to hand combat, and thus the training is not necessarily the best available. It is just the best available for someone not expected to spend most of their time in H2H combat. Thus, the perfect style for the non-H2H combatant. Hence the likes of MCMAP for the US Marines, and the basic levels of Krav Maga for normal Israeli infantry. Special operations forces definitely get better H2H training (e.g. DEVGRU and CAG do get instructors who teach some rather interesting things ranging from Apache knife fighting, Sayoc Kali, and some rather eclectic stuff like P.F.S and S.P.E.A.R; while the Israelis teach harder types of Krav Maga and KAPAP) ...but still ...these guys will spend most of their time practicing on their main weapons.
For the average soldier (read: not part of special operations) the time spent working on their side arm is less than that done by the average police officer, and the Glock is absolutely perfect for the average soldier. A member of DEVGRU or Sayeret can make a case for a different handgun, but the average soldier ...not really (apart from personal taste). The average soldier is a 'non-shooter' when it comes to handguns as compared to i) the amount of time spent on the handgun vs the primary weapon, and ii) compared to even civilian shooters who have decided to put serious time into handgun practice. Consequently, if the Glock is the perfect gun for a non-shooter, the British chose wisely.