I think like any food there will be those that like it or don’t it’s irrelevant that it’s a meat sub in that regard.
I’ve been veggie over 30 years and well remember when there was sod all available! It was either spend loads of time cooking from scratch with vegetables or use less than nice tasting and very limited products from health food shops like unflavoured soya protein etc.
There was beanfeast which gives me horrendous heartburn and came ready flavoured in iirc max 3 different flavours, savoury, bolognese and chilli. And things like sosmix which was a dried soya product designed to be made up into veggie sausages, tasted nice enough but was messy and time consuming to make.
When quorn came on the market it was a huge change for many veggies.
Linda McCartney’s range came out around the same time I think and also meant there was much more choice and availability for veggies.
Regarding the stomach issues - again can happen with any foodstuff. I can’t tolerate spicy food these days, I’ve never been able to manage citrus fruits or juices, instant diarrhoea! And as a veggie I have to watch I actually don’t overdo the pulses as that also affects me.
Weirdly I discovered after turning veggie that red meat upsets my stomach MASSIVELY so, I’d spent my childhood until then having red meat most days as that was the norm for my mum, when I went veggie a lot of the stomach issues I’d had all but disappeared, but labelling/info on food wasn’t yet as good back in the 80’s as it is now and on a few occasions I ate red meat or by products by accident that’s what led me to the discovery, the last time actually landed me in a&e I was so ill. I’ve been VERY careful to avoid since.
Like eating anything new it’s trial and error.
I like most of the quorn products although obviously avoid the spicy ones, I’m not keen on the frozen sausages and prefer the Linda McCartney ones but I like the cocktail sausages.
The mince I like well enough thought the texture is a bit insubstantial so I prefer to use soya mince for that reason. But I will use it in recipes that are fairly quick and well flavoured like bolognese.