I think everyone has a point here. Allow me to kowtow:
Yes, newbies like thick blades because of the machismo factor. Some people buy them because they feel solid, and better worth their money. Some want to hack stuff with them. Some want to pry. Some want to split wood.
I like a hefty blade, myself. Why? Because I have had some blades break and chip on me. They might have been cheap, yes. But it forms an opinion. I abuse my blades every day at work operating a 10 ton recovery wrecker. I currently go between a Lone Wolf T2 and a Camillus HEAT. Both are relatively thick, but ground to a decent edge. They could be sharper, but I NEED them to be stronger and only adequately sharp. I don't ever find a need to cut paper suspended in air during my normal daily routines. I don't ever find myself needing to shave my arm hair during my normal daily routines. But, I do have to pry a little, and I do have to hack very tough nylon and cut very thick plastics to free people or vehicles - which occasionally means I may slip and hit the metal parts these are attached to. Slipping off of a bumper and hitting a radiator brace kills a blade very quickly; prying - even faster. But having one tool I can go to for nearly all my tasks is literally priceless due to time and ease of carry. When I have 'real' prying or cutting jobs I go to my power or much larger equipment in one of the tool boxes. The small jobs all go to a single tool I can whip out in an instant when needed without having to run back to a truck that may have to be 100 yards away up a ravine - the knife.
I have reprofiled the T2 3 times so far due to chipping. I think mine had a bad draw on it. The Camillus HEAT in the frowned upon AUS8 has been doing fine, though. No chips yet. It just gets sharpened more often, and the acid that tends to seep from damaged batteries from car crashes has really etched the blade badly. The S-30V seems to be more resistant.
When it comes to blades of old, it all depends again. Bowies began life as 'frontier blades'. They were relatively thick and handled a great many chores. I doubt Jim Bowie was often seen with an axe. He didn't really need one most the time, as he wasn't with Lewis and Clarke. But he had his Bowie. All the historical Bowies I have seen at the Alamo and from various other historical venues in Texas have been rather thick. They were designed to hack and slash bone, wood, and people as well as pierce and cut. I find even today that 3/16-1/4" thick blades help to balance a Bowie well, retaining the ability to slash and hack, as well as be fast in the hand. Many old Bowies(and old daggers/long knives before the US came to be) were fabricated from broken swords, sabers, cutlasses, etc. That is one of the reasons some of the southern D Guards have such a downward profile - they were made from sabres and cutlasses which had large bellies, as well as being Sheffield inspired. These sabers weren't very thin. They had to hit other sabers or axes or pikes etc. at a gallop when used on horseback. I doubt many we're 5/16th thick(which is the true spine thickness of the Cold Steel Bowies and trailmasters mentioned in previous posts), but I doubt any were 1/8th thick. When you reprofile a wide grind onto such a thick blade, it becomes much lighter than it appears, and yet retains great chopping and hacking ability and strength. This is one of the reasons Striders smaller knives have such wide blades - to allow a 3/16th to 1/4" thick spine to taper(usually flat ground) to a very thin edge, yet still be strong enough for some abuse.
Parrying daggers were almost insanely thin by todays standards, and very very strong still. Made of medium carbon, and often without the requirement of holding an edge for more than 1-2 duels, they could afford to use lower carbon steel and gain some strength vs edge holding. I am currently making a circa 17th century parrying dagger from 5160 barstock specifically for the strength. It will be rather thin in the middle. So I hope the heat treat goes well

This brings me to another point - older knives often had a much lower carbon content(with the notable exception of some Japanese weapons), this would make them stronger for a given thickness VS. some of the high carbon steels available today. Keep that in mind when you compare new to old.
All things being equal, the thicker blade has the advantage in an abusive relationship. But, if one uses the right tool for the job one can go with a thinner blade and not have any problems. But how many Americans go by the rules?
WYK