Thanks for the link, very interesting.
Interesting what he said about the ease of hint-searching ruining puzzles... what he DOESN'T go into, however, is why people would turn to hint-searching so readily instead of trying to solve the puzzle. Gilbert talks about lack of time, and a wide variety of games - so many that to spend a long time "stuck" on a game, being frustrated, when one could be playing something else, seems strange.
What he might not have realised - as he said himself he had more fun DESIGNING games than PLAYING them - is how much the distrust builds up over years of badly-designed puzzles. Almost the entirety of the first Discworld game, and some key puzzles in Simon the Sorcerer 1 and 2 (hush-puppies, anyone?), and then the puzzles of Black Dahlia - these are the main culprits in building within me a certain distrust of puzzles. I'll try to solve them, I'll be game for it as long as the game remains fair. But if the game starts throwing puzzles with inane solutions (in an AGS game, "Crave", when you had to search a dumpster which was next to a stairway with a bannister, you actually had to drop a banana peel in the ground and then slide down the bannister - the PC would gleefuly slide all the way down, slide in the banana peel, and enter the dumpster head-first. The author had brilliant AGS skills but also had serious design issues), then my trust is gone (Broken Sword 4 had some very iffy situations too, where you had some codes you had to enter and then had to manipulate the codes some more in order for them to be accepted - for no reason at all).
The issue isn't "Why should I waste time on this puzzle when there are other games I'll probably enjoy best?", and it takes a long-time player, not a designer to recognise it, but rather "Why should I waste time on this puzzle when I have no idea if it'll be worth it, when I have no idea whether the designer is playing fair?". It's become common for me to hint-search as soon as I'm seriously stumped. Then, based on the solution, I'll smack my head, thinking "I should have got that", and proceed, with a little more faith, more willing to invest some time (which keeps happening in Infocom games, curiously).
Or, instead, I'll think that it was a badly designed puzzle, or it didn't make sense, or whatever. Then I'll gauge whether I'm having enough fun to continue with the game. Sometimes I do, with the hints ready should I need them. Sometimes I don't, and quit the game, and that'll be that.