There may well be other contributing factors than the quite narrow two you offer.
Reading some of Jeremy Leggett's analysis of nuclear in the region, notably Flamanville and Hinkley, is highly enlightening.
From inability to plan or produce sufficiently high quality components, and then challenges getting them into place without damaging them, low quality work being undertaken in the construction process [1], government hiding details of contractual arrangements, a consistent (and predicted) drop in the price of power before and through the lives of these projects, industry players being painted into a corner where they must [try to] grow their business despite the above [2], combined with a surfeit of hubris all round.
Reading some of Jeremy Leggett's analysis of nuclear in the region, notably Flamanville and Hinkley, is highly enlightening.
From inability to plan or produce sufficiently high quality components, and then challenges getting them into place without damaging them, low quality work being undertaken in the construction process [1], government hiding details of contractual arrangements, a consistent (and predicted) drop in the price of power before and through the lives of these projects, industry players being painted into a corner where they must [try to] grow their business despite the above [2], combined with a surfeit of hubris all round.
[1] https://www.theguardian.com/business/2018/apr/10/edf-warns-o...
[2] https://jeremyleggett.net/2016/06/03/the-nuclear-white-eleph...