I disagree with you, Doug. Even the resources of a brand-new computer with the best specs can be exhausted. It all depends on what's currently going on on the computer, on its configuration, etc. You can have nominally great hardware, but if it's misconfigured, that won't help you any.
By all appearances, this game uses more (way more?) computer resources than it could/should. But that doesn't mean the lags are unrelated to the player's computer. There are lots of hidden processes running on any computer and if there's a lag in the game seemingly "out of the blue", it may be caused by a hidden process having become activated (perhaps intermittently activated) on your computer without your being aware of it. Like a regularly scheduled anti-virus scan running automatically in the background, for example.
An illustration of the resources issue... I played a game earlier today. My laptop has 1GB of RAM and I use Google Chrome to play the game. Right after I launched the game window, I noticed RAM go all the way down to zero. The first hole was very slow to load for me & the meter jumped on my first tee shot, so my drive ended up in the rough. So, what I did was close the other Google Chrome window from which I had launched the game window. There were 3 tabs open in it, with this discussion forum.
Boom! Right after I closed that Chrome window where the forum tabs were, the RAM on my computer jumped from just above zero to over 200MB, and stayed that way until the end of my Ladder 9 game. There was hardly ever any meter lag for the rest of the game.
It doesn't seem likely these discussion forums by themselves are as resource-hungry as all that. It may well have been one of the ads displayed on the forum pages that was eating up 200MB of my RAM (one fifth of the entire RAM on my computer).
So, that's just an example for you, Doug. The initial lag in my game and during the first tee shot was clearly related to my PC and the processes running on it – not just the game itself. Although I'm still unable to identify the cause clearly.