It is intentionally and deliberately designed that way.
Reason being....so that you (the owner/buyer of the product) would get discouraged and not want to mess with the hassle, etc. and just take it to an Authorized Service center (hopefully Hustler) and have them do it. Of course if it is not under warranty you (the customer) are going to have to pay for all parts and labor, etc.
That's the way todays many common vehicle engines are now designed.....so that the customer has to take it to the vehicles service center for repairs, maintenance, etc.
Remember it's now all about making $$$$$$$ !