This is a fantastic question and I'm really glad you asked it.
What Goblet of Fire actually says is:
'[...] Harry, if you leave your school list out, I'll get your things for you tomorrow in Diagon Alley. I'm getting everyone else's. There might not be time after the World Cup, the match went on for five days last time.'
'Wow - hope it does this time!' said Harry enthusiastically.
'Well, I certainly don't,' said Percy sanctimoniously. 'I shudder to think what the state of my in-tray would be if I was away from work for five days.'
'Yeah, someone might slip dragon dung in it again, eh, Perce?' said Fred.
'That was a sample of fertiliser from Norway!' said Percy, going very red in the face. 'It was nothing personal!'
'It was,' Fred whispered to Harry, as they got up from the table. 'We sent it.'
Harry Potter and the Goblet of Fire - pp.60-1 - Bloomsbury - Chapter 5, Weasleys' Wizard Wheezes
(I left the joke in because it's a cracker!)
This actually suggests to me that the stark difference between school and professional Quidditch games your question assumes isn't actually what the author is trying to establish here. It seems that professional Quidditch, just like school-level Quidditch, has that quirky, magical, intentionally silly to the Muggle audience characteristic of not having a defined end-point. It ends when the Snitch is caught, who knows in advance when that will be!? Our cast of characters certainly doesn't. Oh those crazy wizards! How quaint and silly.
And I think this is actually borne out. If we go back a page we see that England lost to Transylvania 390 to 10 which doesn't suggest a game that went on for days. Meanwhile the actual World Cup game we get to see doesn't last that long either, it's all over in one evening and the final score is only 160 to 170 (and the goals are shown to come fairly thick and fast, it's not like you can say 'oh well at the professional level you might not get a goal for an hour because of the standard of defence', it doesn't seem to be like that).
I think we're supposed to think that all Quidditch can end at any time. It can go on for a ridiculously long time, it can last 20 seconds.
But I'm with you actually. I think you're right to imagine and deduce that no Hogwarts Quidditch game has likely lasted days and perhaps the average professional game is a bit longer, who knows.
So how could that be explained? Clearly the World Cup stadium was a lot bigger, which presumably gives a Snitch more places to hide. It might also be, as others have suggested, that Snitches have different 'difficulty settings' as it were.
But I think there might be another aspect to this. The World Cup is a knock-out tournament. This tactical element is a big feature of the World Cup match we see. Bulgaria are losing. Krum catches the Snitch, even though it ends the game and seals his team's defeat. Another Seeker might have let the Snitch go and focused only on stopping the opposing Seeker from catching it, but in this case Krum wanted to give his team a more dignified defeat with a close final score and with their Seeker having caught the Snitch. Better than letting Ireland romp away to quadruple figures! But I think most Seekers would probably have let the game continue in that situation.
'What did he catch the Snitch for?' Ron bellowed, even as he jumped up and down, applauding with his hands over his head. 'He ended it when Ireland were a hundred and sixty points ahead, the idiot!'
'He knew they were never going to catch up,' Harry shouted back over all the noise, also applauding loudly, 'the Irish Chasers were too good ... he wanted to end it on his terms, that's all ...'
Harry Potter and the Goblet of Fire - p.103 - Bloomsbury - Chapter 8, The Quidditch World Cup
House Quidditch meanwhile appears to take 'goal difference' into account. Or rather it looks like your scores in individual games accumulate. This can also lead to Seekers delaying capturing the Snitch, as we see in the Prisoner of Azkaban:
Slytherin were leading the tournament by exactly two hundred points. This meant (as Wood constantly reminded his team) that they needed to win the match by more than that amount to win the Cup. It also meant that the burden of winning fell largely on Harry, because capturing the Snitch was worth one hundred and fifty points.
'So you must only catch it if we're more than fifty points up,' Wood told Harry constantly. 'Only if we're more than fifty points up, Harry, or we win the match but lose the Cup. You've got that, haven't you? You must only catch the Snitch if we're -'
'I KNOW, OLIVER!' Harry yelled.
Harry Potter and the Prisoner of Azkaban - p.221 - Bloomsbury - Chapter 15, The Quidditch Final
But I can imagine it might make more sense in a round-robin tournament to take those 150 points even at the cost of a lost game than it would in a knockout tournament where a loss is final.
It's also easy to see that the longer a game goes on and the higher the score becomes, the less effect 150 points will have on the score (particularly as scores from previous games don't accumulate). There is plenty of evidence that House Quidditch is a lot slower than professional Quidditch as the teams aren't as good. If we imagine that the action is a bit slower and the goals a bit less frequent then it might well be that at schoolboy level those 150 points are almost always enough to win the game, whereas at professional level games might ebb and flow a little bit more and it might be more a question of endurance. And if the Snitch is harder to catch you can see how professional Quidditch would then become more of a long game (literally and metaphorically).