I've defended them but there's consistent issues that probably comes down to Castore just not being an established enough brand for mass production and using a cheap factory.
I've said on here from before the kits were released that we would regret our desire for an embroidered badge because the Castore shirts were too thin for it. Look at the press release pictures and they have the same pulling. They probably made the decision not to embroider the Castore one because it's too detailed and has too many close gaps for a thin material. I don't know if it's changed, but I don't think any of Castore's normal range has embroidery because their badge and the small writing underneath is just not made for embroidery. I've not got all the tops to compare but this seasons are definitely much thinner than anything I have, which doesn't help with our badge. The thinness is something Castore brand as performance based but it could just be cost effective.
That could be overcome with quality template designs, semi-modern machines, and the machinists doing their job properly though. It's clear Castore don't have access to as good manufacturers as the others, their brand does in Portugal but it's second rate at best manufacturers for our stuff.
The thread count is too high and too thick and that could be fine with a better template and better machines won't jam as much so no bunching and bent writing. Old machines will jam all the time meaning the shirt stops moving but the needle keeps going, the cheap machines don't have a auto stop so it relies on the worker to stop it. These workers are just trying to push through and making only basic fixes to get the machine running again. The brands you mention pretty much have a monopoly on the best manufacturers during kit season though. I think one of the brothers maybe spoke about that in the interview with Mark or around that time as the reason for going to Turkey or China.
Then with quality control there's just more care put into better brands. Where I used to work, we done most of Scotland's school uniforms so there was huge rushes during a short period. We were pretty much told to take the time to make sure the 'better' schools were perfect and don't waste time fixing the issues on the 'lesser' schools. It will be the same with Castore until they establish themselves and have a bit of power with manufacturers.
I said to you last week or so that I thought a lot of the print problems are user error because the prints are actually quite good. But looking more at it now it's probably more likely the print material is decent to up the cost to Castore, the same as the thick overused thread, and over stitched interior, because a lot of pricing is done on thread and stitch count and thickness of print. Then they are skimping on the heat press time to get more done so it's peeling in the wash or under heat. Doing a 10 second instead of 15 second press will get you a third more done and they'll get through a few washes if you're lucky. That and the rushed embroidery points to a cheap factory that places quotas on their workers and docks them for wastage.