Many boat people don't know how to maintain their boat, nor want to learn. It's a boat, right! So let it sit outside in the rain and snow - it'll be OK.
I always knew that jetski people were even worse. The old adage - run hard and put away wet. For that reason my first PWC was bought brand new. I also bought a shop manual. My maintenance was by the book.
The one in question was a 1999 GTI. Bottom line - it was crap. Problems with the oil injection system, starting issues, oil tank cracked. Yada, yada....to many problems to mention. The machine spent more time in the shop than in the water.
Then we bought a 4-stroke. 14 years trouble-free. Traded it in on another - 10 more good years. Altogether the family has owned four 4-strokes. Not a single one ever went back. We do all our own maintenance.
Given the choice, if I could not afford a 4-stroke I wouldn't own one. JMHO.