Is it reputation based on fact or hearsay?

I'd wager that Rover's reliability based on real fact on a whole was no worse than any of the manufacturer you've listed above. On product specifically, Rover was let down by the MGF (largely handmade) which nearly always finished bottom of any warranty survey. 75s, 45s and 25s compared very well against any of the above listed contemporaries in any warranty/reliability survey.

Why Rover never shifted its 'poor' reputation? I have no idea, it wasn't as if the company didn't really try hard over the last few years to do something about it.

What really gets my goat is the whole HGF trouble.

The early 2.5KV6's were made by hand before going to full plant. The early 1.8's really were pushing the limit of the 4-pot K and it was BMW (shock!) bean counting that did silly things like replace metal locator dowels for plastic on the head to cylinder block and downgrade the gasket component. These were fixed many, many years ago.

Admittedly Powertrain did have a fix for the thermal shocking that seemed to plague MGF owners (and also Discovery owners) with a pressure sensitive thermostat and Rover management were guilty of not implementing that fix. Also Lotus messed around with the K too creating imbalances in the engine creating pressure on the 'sandwich' assembly, again, creating the potential for HGF problems on Elise and Exige models.

Oddly, of the 3 MILLION K-series engines made from 1982 to 2006, they suffered a failure rate of 0.03% Most of those 1.8 normally aspirated. That means the 1.1, 1.4, 1.6, 1.8T, 2.0 KV6 and 2.5KV6 are very reliable indeed.

Compare that to the 3 MILLION car recall by VAG group for coil pack problems across most of the range.

You have to remember the Rover and its Powertrain engineers had over 60 years of working with aluminium engines (not just heads). Even comparing a K now to brand new engines, it's still hard to beat for power to weight or economy.

As for Rover's being unreliable, I'll leave you with this.

The Rover 75 only ever had two recalls, both minor. The BMW 3 Series (E46) had six. Renault Laguna (Mk2) has had nine. VW Passat (Mk4) had three. Mercedes C-Class (W203) had six.

Honda Accord only one.

Incidentally, the Rover 800 only had two recalls as well.

Rover's car on the whole came out on a par (slightly better) than Nissan.

Not bad company, keeping up with the Japanese.

I'd say the main problem was the fact that the product line up, with a bit of an exception for the 75, was far too aged. People aren't prepared to pay fairly high prices for 15 year old car designs with a new dashboard and a few spoilers tacked on.

Granted Rover did very well in 'MGing' some of the models, but without the cash to develop a new model, the writing was on the wall.

Constant rumours of meltdown in the final years only accelerated people's movements away from Rover, with the thought of missing warranties in peoples minds.