If I had a rough tailpiece, I would ask and expect the company to make it right.
You're quite correct of course. Keep in mind that what you said is applicable only if a company, or their representative, is willing to do that (make it right) in a material manner, and not just pay lip-service and take the view that they can do no wrong.
Manufacturers often play the "blame the intermediary" game and often the intermediary plays the "blame the manufacturer" game, or is simply unwilling to bother chasing the manufacturer, for many, many reasons.
I'll give you a personal example. I have a authorised Rickenbacker dealer here in my city. There is absolutely no way I can get new replacement parts for a Rickenbacker here from them. I have asked..."ah", they say, "we have no distributor in the country anymore" ...
I have written Rickenbacker if they would see fit to sell me a part, readily available on their site, but although they have an eBay store that now ships worldwide (although the part I am referring to is not available throught their eBay outlet), they are not willing to sell it to me from their "boutique". They know very well that there are no distributors here so it would make a little sense that they would see my request as not outlandish. Keep in mind that although there may be similar parts available through an internet dealer in the states, it may be very difficult for those that do not have access to the internet to deal with them and many people are still reticent about sending credit card details over the net to an unknown (to them) quantity.
Although I have other avenues to obtaining these parts from trusted sources, nevertheless this makes it very difficult for many that have Rickenbackers, to maintain them in a manner they would like - parts do wear out.
If the company has decided not to, or is unwilling to, have a distributor here for whatever reason, I would think it would behove that company (if it is still in business) to maintain some sort of local access for their previous customers.
There was a time for example, where Citroens were not available here, however new genuine parts for them were always available, either directly from Citroen itself or an intermediary here.
So, getting back to your statement, of course many people, I think, would and will gladly contact their first known avenue of recourse, thereafter if they have no resolution to their problem I would think any normal person would try to approach the manufacturer.
I would think that the sheer frustration of not getting anywhere sensible, would drive many to forums such as this to discuss their experiences, don't you think?